ejercicios de estructuras isostáticas. analisis estructural

45,797 views 190 slides Sep 06, 2016
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About This Presentation

curso de análisis estructural


Slide Content

UNIVERSIDAD MAYOR DE SAN SIMON
FACULTAD DE CIENCIAS Y TECNOLOGIA
CARRERA DE INGENIERIA CIVIL



“APOYO DIDÁCTICO PARA LA ENSEÑANZA Y
APRENDIZAJE DE LA ASIGNATURA DE ESTRUCTURAS
ISOSTÁTICAS”
“TEXTO ESTUDIANTE ”



TRABAJO DIRIJIDO, POR ADSCRIPCIÓ N, PARA OPTAR AL
DIPLOMA ACAD ÉMICO DE LICENCIATURA EN
INGENIERÍA CIVIL


PRESENTADO POR:
 DENNIS BERNARDO TORRICO ARAUCO
 RAUL LIENDO UDAETA
TUTOR:
Ing. Oscar Antezana Mendoza


COCHABAMBA – BOLIVIA
MARZO DE 2006

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  1  -U
U
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CAPITULO 1 
 
 
 
 
FUNDAMENTOS DE LA ESTATICA Y 
ENFOQUE VECTORIAL 
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1.1   OBJETIVO GENERAL.    
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1.2   OBJETIVOS ESPECIFICOS. 
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1.3 FUERZA.  
c+ 1(6At+ 64 .+ +mmof- )6 (- m(6AP3 437A6 32A3L =(6 PA3)(m6 6- 6426 M.2oS3 (-+ S3)o1om+mof- 
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"mUyoaSmSUSaósoFavomiUsoUsiUmoCiaFaFUSsUimFUsFdYycdyYmFUsFUiaeYmTU$aiv%YmóvTUdvosimSmíUUU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  2  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  3  -U
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srsYcacavíU
Ejercicio #1 
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Solución.- 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  4  -U
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1.4  VECTOR DE POSICION. 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  5  -U
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Figura 1.3 
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1.5  VECTOR DE DEZSPLAZAMIENTO. 
 
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niU SsFuimtmóasodvU mU ósoySvU ivU YsuYsFsodmóvFU uvYU yomU FvimU isdYmU ómg#FcyimU lysU mly'U imU
óvFdYmYsóvFUsoUos%YadmU3TUusYvU!mgUóyc!mFUvdYmFUómosYmFíUU
noUimUMa%U+í;UóvFdYmóvFUlysUsiUSsFuimtmóasodvUumYmUaYUSsUIU!mFdmUEUsFUyomUi'osmUYscdmUlysU
yosUsFdvFUuyodvFTUsóuastmUsoUIUgUdsYóaomUsoUEUSaYa%aSmU!mcamUEíU ymoSvUsiUcysYuvUFsUóys sUSsU
ómosYmUlysU mgmUgU ysi mUmiUuyodvUaoacamiTUsiUSsFuimtmóasodvUsFUcsYvíUnFUaóuvYdmodsUSmYFsUcysodmU
lysUsiUSsFuimtmóasodvUovUsFdCUYsimcavomSvUcvoUimUSaFdmocamUYscvYYaSmíU
A
B
P
UU U U U
A
B
P
U
Figura 1.4 (a)          Figura 1.4 (b)  

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  6  -U
U
/móvFUmUYsuYsFsodmYUimUmagnitudUSsUyoU scdvYU*imUivo%adySUsoUsiUcmFvUSsiUSsFuimtmóasodv,U
uvYUimUóaFómUisdYmUSsiU scdvYUusYvUovUsoUos%YadmUvU](β⇒<+
F→2⇒(γ,δ+[+δ,⇔[+δβ+
P,U4
PP
rr
=U
[∑+δβ−(⇒(√(⇒+β⇔+δ,⇔[+δβ++βθ+,⇒+βθ√→⇔→∑+,⇒+⇒0sYv,UgUFasóuYsUsFUuvFada víU
8yuvosóvFU m!vYmU lysU yomU umYd'cyimU dasosU yoU SsFuimtmóasodvU
PTU Fs%yaSvU uvYU yoU
SsFuimtmóasodvU
QíU niU YsFyidmSvU sFU siU óaFóvU lysU FaU FsU !yeasYmU cvoFaSsYmSvU umYdasoSvU SsiU óaFóvU
uyodvUaoacamiUyoU#oacvUSsFuimtmóasodvU
RUcvóvUuvSsóvFU sYUsoUimUMa%yYmíU
U
U
Figura 1.5 
U
"vU lysU soU F'óevivFU uvSsóvFU s(uYsFmYU
R  =  P  +  QTU mU sFdsU  scdvYU FsU ivU iimómUsuma vU
resultante.+[⇒β∑+→γβ⇒√(⇒+′,β+→′, +βθγ→[θ+θ,→⇒δ[+)β√γ[∑βθ+∫UovUsFUimUFaóuisUFyómUmi%seYmacmUSsU
θ,θ+δ,⇔[θ+θ(⇒[+′,β+δβ]β[θ+γ[→∑+β⇒+√,β⇒γ→+θ,θ+δ(YsccavosFíUU
U
U
Figura 1.6U
U
(β⇒δ[+⇔→+−(2+⋅↑+θβ+δβδ,√β+′,β<+++
U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
()
+2+2+2rrrr
rrrrr
−=−+=δ U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  7  -U
U
UUUUUUUUUUUUUUUUU+2δ
r
UU"imómSvU scdvYUSsUSsFuimtmóasodvUsodYsU
2+PyPU
U
8asóuYsUFsUuysSsUmFvcamYUmUyoUuyodvUFyUYsFuscda vU β√γ[∑+δβ+[θ(√(⇒+
[ ] [ ]
2222++++00000ZYXrZYXr ==
rr
U
[ ][ ]
+++222+20000ZYXZYX −=δ
r
U
[ ]
+2+2+2+200ZZYYXX −−−=δ
r
U
( ) ( ) ( )
2
+2
2
+2
2
+2
ZZYYXX −+−+−⇔δ
r
U
δ
r
+=θ+⇔→+−∑,⇔→+δβ+δ(θγ→⇒√(→+β⇒γ∑β+δ[θ+,⇒γ[θ++UgU32U
Ejercicio #2 
→δ[θ+⇔[θ+,⇒γ[θ++USsUcvvYSsomSmFU*2T56T:,UósdYvFTU32USsUcvvYSsomSmFU*:T+T6,UósdYvFTU36USsU
cvvYSsomSmFU*5+T:T6,UósdYvFíU
m,
 G→⇔⇔→∑+β⇔+)β√γ[∑+δβ+[θ(√(⇒+β⇒γ∑β+2UgU36U
e,
 GmiimYUsiU scdvYUSsUSsFuimtmóasodvUsodYsU32UgU36U
c,
 GmiimYUimUSaFdmocamUsodYsU3+UgU32U
Solución.-                                                                                      A       
m,U→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUUUU→UUUUUUUUUUUU→U
UUUUY+UU⇔U[2T56TU:]UU⇔UU2UaUUU56UrUUUHU:U$U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUvU3+U
UU
→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUUU→UUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU δ26U
UUY
2UUU⇔U[:TU+TU6]U⇔U:UaUHU+UrUH6U$UUUUUUUUUUUUUUUUUUUUUU36U>UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU>U3 2U
U
UUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUU→UUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU @UU
UUUY
6UU⇔U[5+TU:TU6]U⇔U5+UaUH:UrUHU6U$U
U
e,UU
→UUUUUUUUUUU→UUUUUU→U
UUUUUδ26U⇔UY6UIUY2U⇔[5+TU:TU6]U5U[:TU+TU6]UUUUUUUUUUUUUUUUUUUUUUUU
→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU?U
δ
26U4U[5+T5+TU:]UUU
c,UUU
→UUUUUUUUUUUUU→UUUUU→U
UUUUUUδ +2U⇔UUY2UIUY+U⇔U[:TU+TU6]U5U[2T56TU:] UUU
U
UUUU→UUUUUUUUUUUU
U
UUδ
+2UUU⇔U[52TU;TU6]U
U
U
δ
+2
→
U4U( )
222
6;2++−
UUU
4U7TU6=U*ó,USsUSaFdmocamU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  8  -U
U
1.6   MOMENTO DE UNA FUERZA CON RESPECTO A UN PUNTO . 
 voFaSsYsóvFUyomUMysYtmU-UlysUmcd#mUFveYsUyoUcysYuvUY'%aSvUcvóvUFsUóysFdYmUsoUimUMa%yYmUU
+íJíU vóvUFmesóvFUimUMysYtmU-UFsUYsuYsFsodmUuvYUyoU)β√γ[∑+′,β+δβ−(⇒β+θ,+→2⇒(γ,δ+∫+δ(∑β√√(⇒⋅+∞(⇒+
sóemY%vTUsiUsMscdvUSsUimUMysYtmUFveYsUsiUcysYuvUY'%(δ[+δββ⇒δβ+γ→](⇒+δβ+θ,+,⇒γ[+δβ+→⇔(√→√(⇒+⋅+
3→+[θ(√(⇒++δβ++θβ+δβ−(⇒β+√[⇒)β⇒(β⇒γββ⇒γβ++[∑+βiU scdvYUYUlysUyosUsiUuyodvUSsUYsMsYsocamUMarvU>U
cvoUsiUuyodvU30UsFdsU scdvYUFsUcvovcsUcvóvU scdvYUSβ+[θ(√(⇒+δβ+⋅+=⇔+)β√γ[∑+δβ+[θ(√(⇒+
rUgUimU
MysYtmU
FUSsMaosoUsiUuimovUóvFdYmSvUsoUimUMa%yYmU+íJU
U
Figura 1.7 
β−(⇒(∑β[θ+β⇔+[β⇒γ[+δβ++√[⇒+∑βθβ√γ[+→+Τ+√[[+βiUuYvSycdvU scdvYamiUSsU rUgUF. 
 
M
o = r * FU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUKU
YU⇔+β√γ[∑+δβ+[θ(√(⇒+δβ++
                                                                                                          →→→→            →→→→     →→→→ 
M P1 = δδδδ * F1 
                                                                   →→→→ 
δU⇔U/scdvYUSsUSsFuimtmóasodvUsodYsU3+UgU32U
U
niUóvósodvUMoUSsesUFsYUusYusoSacyimYUmiUuimovUlysUcvodasosUmU>UgUmU FíUniUFsodaSvUSsUMo UFsU
δβ−(⇒β+[∑+β⇔+θβ⇒γ(δ[+δβ+∑[γ→√(⇒+′,β+[δ∑ →+⇔⇔β)→∑UsiU scdvYU
 rUmUFsYUcviaosmiUcvoUsiU scdvYUF0UusYvU
βθγ→+ ∑[γ→√(⇒+ βθ+ ⇔→+ ∑[γ→√(⇒+ ′,β+
FU dasoSsU mU aóuYaóaYU miU cysYuvíU IF'TU siU FsodaSvU SsiU óvósodvU MoU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  9  -U
U
√→∑→√γβ∑(•→+ β⇔+ θβ⇒γ(δ[+ δβ+ ⇔→+ ∑[γ→√(⇒+ ′,β  F+ γ(β⇒δβ+ →+ (∑((∑+ →⇔+ √,β∑[+ ∑ 2(δ[+ βθγ→+ ∑[γ→√(⇒+FsYCU
veFsY mSmUcvóvUcvodYmYamUmUimUSsUimFUm%yrmFUSsiUYsivrUuvYUyoUveFsY mSvYUFadymSvUsoUsiUs(dYsóvUSsU
MoíU
Τγ∑→+→⇒β∑→+δβ+βθγ→]⇔β√β∑+⇔→+∑β⇔→√(⇒+β⇒γ∑β+β⇔+θβ⇒γaSvUSsU
Mo ∫+β⇔+θβ⇒γ(δ[+δβ+⇔→+∑[γ→√(⇒+δβ⇔+√,β∑[+
Y'%aSvUsFUsiUFyóaoaFdYmSvUuvYUimUYs%imUSsUimUómovUSβ∑β√ϕ→<+√(β∑∑β+θ,+→⇒[+δβ∑β√ϕ→+→⇒γβ⇒(β⇒δ[+β⇔+
δβδ[+,⇔2→∑+βγβ⇒δ(δ[ω+θ[θγ⇒2→⇔→+δβ+γ→⇔+[δ[+′,β+θ,θ+δβδ[θ+(⇒δ(′,β⇒+β⇔+θβ⇒γ(δ[+δβ+∑[γ→√(⇒+′,β+⇔→+
MysYtmU
FUdasoSsUmUaóumYdaYisUmiUcysYuvUY'%aSv0UFyUSsSvUuyi%mYUaoSacmYmUsiUFsodaSvUSsiUóvósodvU MoíU
-aomiósodsTUiimómoSvU
θ+→⇔+∆⇒2,⇔[+√[∑β⇒δ(δ[+β⇒γ∑β+⇔→θ+⇔ ⇒β→θ+δβ+→√√(⇒+δsiU scdvYUSsU
[θ(√(⇒+
rUgUimUMysYtmUFU!miimóvFUlysUsiUóvósodvUSsUF+√[⇒+∑βθβ√γ[+→+Τ+βθ<+
Mo = r F. sen θθθθ = F d 
 
Ejercicio #3 
 
→δ→+⇔→+−,β∑•→+[+TU2T52]UdvosimSmFTUlysUumFmUuvYUsiUuyodvU3++ωωφ+βγ∑[θ⋅+βγβ∑(⇒→∑+β⇔+
óvósodvUSsUimUMysYtmUYsFuscdvUsiUuyodvU3
2U*:TU2T5+,íU
Solución.-                                                                UUUUUUUUUUUUUUUUUUUU→UUUUUUUUUUUUUUUAU
UUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU UUδ2+U
UUUY
+⇔U[2T+T6]UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU3 2UvUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUvU3+UUU
UUUU→U U
UUUY6UU⇔U[:TU2T5+]UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU@U
→UUUUUUUUUUUU→UUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
δ2+U⇔UY+UIUY2U⇔U[2TU+T6]5[:TU2T5+]UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU-U
→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
δ2+U⇔U[2T5+T;]U scdvYUSsFuimtmóasodvUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU-U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU?U
→UUUUUUUUUU→UUUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU UUUUUUUUUUUUUUUUUUUUUUUUU
F
2U4Uδ2+ULU-U
U
U→UUUUUUUUU→UUUUUUUUU→U
UUUUUUU2UU5+UUU;UU
F
2U4Uδ2+ULU-U4UUUUU+UUU2UU52UUUUU4UU59UaUHU=UrUHU7U$U4U[59TU=T7U]U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUaUUUUrUUU$U
U

U
F
2U4UU√U*59,
2
UHU*=,
2
UHU*7,
2
U
→U
F2U4U++TU=9UdvoMóU
U
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  10  -U
U
1.7   MOMENTO DE UNA FUERZA RESPECTO DE UN EJE. 
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
I!vYmUlysUFsU!moUmyósodmSvUoysFdYvFUcvovcaóasodvFUSsUmi%seYmU scdvYamiTUaodYvSycaYsóvFUyoU
oys vU cvocsudvTU siU cvocsudvU SsiU óvósodvU SsU yomU MysYtmU cvoU YsFuscdvU mU yoU srsíU  voFaSsYmYsóvFU
oys mósodsU yomU MysYtmU -U lysU mcd#mU FveYsU yoU cysYuvU Y'%aSvU gU siU óvósodvU F
vU SsU sFmU MysYtmU cvoU
YsFuscdvUmUimU*Ma%U+í=,íUU
U
Figura 1.8 
m,UnoUsiU%YmMacvUFsUuysSsUveFsY mYUlysUsiUsrsUsFUusYusoSacyimYUmiUuimovU))U
e,UniUuyodvU3UusYdsoscsUmiUuimovU))U
c,UniUuyodvUmUsFUimUdYmtmUSsiUsrsUsoUsiUuimovU
S,U
+F
r
UsFUimUcvóuvosodsUSsUF
r
UcvodsoaSmUsoUsiUuimovU))U
s,U
2F
r
UsFUimUcvóuvosodsUSsUF
r
UumYmisimUmiUsrsU
δ[⇒δβ<+
F
mU =UFvósodvUSsUMysYtmTUYsFuscdvUSsUaUvUcymilyasYUuyodvUSsUsFsUsrsíUUUUUUUUUUUUUUUUUU
UUUUUUUUUU
UUUUU
Ee
r
++≤+=θ+β⇔+)β√γ[∑+,⇒(γ→∑([+β⇒+⇔→+δ(∑β√√(⇒+δβ⇔+βαβ⋅+
U
[⇒δβ+βθγβ+[β⇒γ[+θβ+⇔[+β∑βθ→+√[[<+
EE
eMM
rr
UL
m
=  
  ∞β+ √[⇒√⇔,∫β+ δβ+ ⇔→+ δβ−(⇒(√(⇒+ δβ+ [β⇒γ[+ δβ+ ,⇒→+ −,β∑tmU cvoU YsFuscdvU mU yoU srsTU lysU siU
óvósodvUSsU-UcvoUYsFuscdvUmUyoUsrsUcvvYSsomSvUsFUa%ymiUmimUcvóuvosodsUF
mUcvoUYsFuscdvUmUSac!vU
srsíU8yFdadygsoSvUFycsFa mósodsUcmSmUyovUSsUivFU scdvYsFUyoadmYavFUaTUrTU$TUuvYUs
nTUcvóuYvemóvFUlysU
imFU s(uYsFavosFU mFaU vedsoaSmFU SsU ivFU óvósodvFU SsU -UcvoU YsFuscdvU mU ivFU srsFU cvvYSsomSvFU FvoTU
YsFuscda mósodsTUa%ymisFUmUimFUs(uYsFavosFUSsUimFUcvóuvosodsFUSsiUóvósodvUF
mUSsU-UcvoUYsFuscdvUmU
3íUU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  11  -U
U
Ejercicio #4   
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU U UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU →UUUUUUUUUUUUUUUUUUUUU
UUUUUUUUU"vFU3yodvFU3
+U*:T52T+,UósdYvFUgU32U*6T52T+,USsMaosoUyoUsrsUsoUsiUsFumcavTUcasYdmUMysYtmUU-U [2TU6T+]U
N%íUumFmUuvYUsiUuyodvU3
:+πωπω⌠⋅+βγβ∑(⇒→∑+β⇔+[β⇒γ[+δβ+⇔→+−,β∑•→+∑βθscdvUSsiUsrsíU
U
Solución.- 
U→U
3
23+U⇔U[56TU:T+]UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU3 +UvU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUnU
UUUU
→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUsUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
323+U4U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  12  -U
U
UUUUUUUU U U U 4U59í7;UN%MóíU
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UUUUUUUU U U U 4U9í7;UN%MóíU
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1.8   TEOREMA DE VARIGNON. 
 
"mU uYvuasSmSU SaFdYaeyda mU SsU ivFU uYvSycdvFU  scdvYamisFU uysSsU ydaiatmYFsU umYmU SsdsYóaomYU siU
óvósodvUSsUimUYsFyidmodsUSsU mYamFUMysYtmFUcvocyYYsodsFíU8aU mYamFUMysYtmFU-
+TU-2TOOOíFsUmuiacmoUmiU
(θ[+,⇒γ[+ω+∫+θ(+⇔⇔→→[θ+∑+→⇔+)β√γ[∑+δβ+[θ(√(⇒+δβ+ω+θβ+√[⇒√⇔,∫β+(⇒βδ(→γ→β⇒γβ+′,β<+
YULU*-
+UHU-2UHUOOí,U4UYULU-+UHUYULU-2UHUOOOU
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Figura 1.9 
noUumimeYmFTUsiUóvósodvUcvoUYsFuscdvUmUyoUuyodvUSmSvU>USsUimUóaFómUYsFyidmodsUSsU mYamFU
MysYtmFUcvocyYYsodsFUsFUa%ymiUmUimUFyómUSsUivFUóvósodvFUSsUimFUMysYtmFUcvoUYsFuscdvUmiUóaFóvUuyodvU
Τ⋅+ 3→+ ∑β⇔→√(⇒+ δβ+ ⇔→+ 2∑→−(√→+ ϕ→√β+ [θ(]⇔β+ ⇔→+ δβγβ∑(⇒→√(⇒+ δβ⇔+ [β⇒γ[+ δβ+ ,⇒→+ −,β∑•→+ + [∑+ β⇔+
cmicyivUSsUivFUóvósodvFUSsUSvFUvUómFUMysYtmFUcvóuvosodsFíUUU
"mUMysYtmU-UFsUSsFcvóuvosUsoUUU-U4U-
+UHU-2UH-6U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUU→UUUUUU→UUUUUUUU→UUUUUUUU→UUUUUUUUUUUU→U
⇒UFnU4UFULUsU4U[YULU*-+UHU-2UHU-6,]ULUsU
[⇒δβ<++++++++++++++++++++++++
                  →→→→      →→→→     →→→→       →→→→      →→→→    →→→→       →→→→      →→→→     →→→→ U
ME  =  (r * F1) .e + (r * F2).e + (r * F3). e 
 
PsvYsómUóvósodvUSsUyomUMysYtmUYsFuscdvUSsUyoUuyodvU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  13  -U
U
1.9   PAR DE FUERZAS – MOMENTO DEL PAR. 
 
8sUSacsUlysUSvFUMysYtmFUFUgU–FUMvYómoUyoUumYUFaUdasosoUimUóaFómUóm%oadySTUSaYscca3e tYdj 
FsodaSvUcvodYmYavTU sYUMa%yYmU+í+:U
U
Figura 1.10 
 
U nFUs aSsodsUlysUimUFyómUSsUivFUcvóuvosodsFUSsUimFUsjv prYdaóv Ye cróForEYd sEdYccE3e Yv 
csYvíU8aoUsóemY%vTUimUFyómUSsUivFUóvósodvFUSsUimFUSvFUMysYtmFUcvoUYsFuscdvUmUyoUuyodvUSmSvUovUsFU
csYvíUIyolysUimFUMysYtmFUovUSsFuimtmoUmiUcysYuvUFveYsUsiUlysUmcd#moUsiimFUdasoSsoUmUaóuYaóaYisUyoU
njxEnEYeXj sY djXócE3e  
 
Figura 1.11 
 
U 1suYsFsodmoSvUuvYUrAUgUrB Fjv xYcXjdYv sY tjvEcE3e sY Fjv treXjv sY ótFEcócE3e sY  FU@U– FUSsU
imUMa%yYmU+í++UsocvodYmóvFUlysUimUFyómUSsUivFUóvósoXjv sY Fóv sjv prYdaóv cje dYvtYcXj ó w Yv1 
rA * F + rB * (-F) = (rA – rB) * F 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  14  -U
U
U 1sóuimtmoSvUrAUIUrB 4UrTUSvoSsUYUsFUsiU scdvYUlysUyosUivFUuyodvFUSsUmuiacm√(⇒+δβ+⇔→θ+δ[θ+
MysYtmFTUcvociyaóvFUlysUimUFyómUSsUivFUóvósodvFUSsU-UgUI-UcvoUYsFuscdvUmU>UFsUYsuYsFsodmoUuvYUsiU
)β√γ[∑<+
Mo = r * FUUUUUUUUUUUUUUUUUUUUUUUUU*+,U
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⇔→θ+δ[θ+−,β∑•→θ+∫+θ,+→2⇒(γ,δ+βθ<+
Mo = r.F.senθθθθ = FdUUUUUUUUUUUUUU*2,U
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+ [⇒δβ+δ+βθ+⇔→+δ(θγ→⇒√(→+β∑β⇒δ(√,⇔→∑+β⇒γ∑β+⇔→θ+⇔ ⇒β→θ+δβ+→√√(⇒+δβ+
FUgU–FTUgUsiUFsodaSvUSsUMoU
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U  vóvU siU  scdvYU
r
r
+ β⇒+ + βθ+ (⇒δββ⇒δ(β⇒γβ+ δβ+ ⇔→+ β⇔β√√(⇒+ δβ⇔+ [∑(2β⇒+>U SsU ivFU srsFU
cvvYSsomSvFTUFsUvedsoSY'mUsiUóaFóvUYsFyidmSvUFaUivFUóvósodvFUSsU
FU@U– FUFsU!yeasYmoUcmicyimSvUcvoU
YsFuscdvUmUyoUuyodvUSaMsYsodsU>

íU3vYUdmodvTUsiUóvósodvUFUSsUyoUumYUsFUyoU scdvYUiaeYsUlysUuysSsU
muiacmYFsUsoUcymilyasYUuyodvUcvóvUFsU sUsoUimU%YmMacmíU
U
Figura 1.12 
+ β+⇔→+δβ−(⇒(√(⇒+δβ⇔+[β⇒γ[+δβ+,⇒+→∑ω+θβ+√[⇒√⇔,∫sUlysUSvFUumYsFTUyovUMvYómSvUuvYUimFU
MysYtmFU
F1UgU-F1TUgUsiUvdYvUuvYUimFUMysYtmFUF2UgU5F2  cvóvUFsU sUsoUimUMa%yYmU+í+6U*m,UgU*e,,UdsoSYCoU
óvósodvFUa%ymisFUFaUgUFvivUFa0UivFUSvFUumYsFUsFdCoUsoUuimovFUumYmisivFUvUsoUsiUóaFóvUuimovUgUdasosoU
β⇔+(θ[+θβ⇒γ(δ[<+++++++++++++
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+S+U4U-2S2U
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  Figura 1.13 (a)                                 Fi gura 1.13 (b) 
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3→+β∑βθ(⇒<    MO = δδδδ * F  YsuYsFsodmUsiUóvósodv Ssi PAR DE FUERZAS 
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  15  -U
U
Ejercicio #5U
+ →δ[θ+⇔[θ+→∑βθ+δβ+⇔→+−(2,∑→+⋅+θβ+(δβ+δβγβ∑(⇒mYUimUFyómUSsUivFUóvósodvFUumYsFíU
+ [⇒δβ<+{
+UgU 6UusYdsoscsoUmiUuimovU@ATU 2UusYdsoscsUmiUuimovUαUumYmisivU?AíUU
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Figura 1.14 
+ ∞β+γ(β⇒β<+
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
→UUUUUUUUUUUUUUU→U
m,UFvósodvUSsUivFUumYsFUUUUUUFc+U4U9UaU4U[9TU:TU:]UdíóUUUUUUUUUUUUUUUUUUUUUUUUUUU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
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+++++++++=θ+δβ√(∑<+
para sumar pares se debe sumar los momentos de los pares U
1.10   TRASLACION DE UNA FUERZA A UNA POSICION PARA LELA. 
 
U 8sUóysFdYmUyomUMysYtmUgUFsUSsFsmUdYmFimSmYimUmUyom+[θ(√(⇒+→∑→⇔β⇔→+′,β+→θ→+[∑+β⇔+,⇒γ[+⋅+
 vóvUFsU sUsoUimUMa%yYmU+í+7U
U
Figura 1.15 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  16  -U
U
UU niUuYvcsSaóasodvUumYmUdYmFimSmYUyomUMysYtmUmUcasYγ→+[θ(√(⇒+→∑→⇔β⇔→+δ→δ→+√[⇒θ(θγβ+β⇒++++
+⇔[θ+θ(2,(β⇒γβθ+→θ[θ<+
+,
 ∞β+γ∑→θ⇔→δ→+⇔→+−,β∑•→+→+⇔→+⇒,β)→+[θ(√(⇒+→⇒γβ⇒(β⇒δ[+θ,+δ(∑β√√(⇒ω+→2⇒(γ,δω+∫+θβ⇒γ(δ[⋅+
2,
 ∞β+→C→δβ+⇔→+−,β∑•→+θ(γ∑(√→+β⇒+⇔→+δ(∑β√√(⇒+δβ+γ∑→FimSvU
6,
 8sUaociygsUsiUóvósodvUSsiUumYUvcmFavomSvUuvYUimUMys∑•→+∫+θ,+θ(γ∑(√→⋅+
U U
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umYUcUMvYómSvUuvYUF
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cysYuvíU8sU!mU aFdvUlysUyosUMysYtmUFsUuysSsUSsFuimt→∑+θ[]∑β+θ,+⇔ ⇒β→+δβ+→√√(⇒+∫+β⇔+β−β√γ[+θ[]∑β+β⇔+
√,β∑[+⇒[+θβ+[δ(−(√→+γ→⇒γ[+→∑→+γ∑→θ⇔→√(⇒+√[[+→∑→+∑[γ→√(⇒⋅+∆θ +(θ[+θβ+ϕ→+δ(√ϕ[+′,β+,⇒+→∑ω+
uvYU FsYU yoU  scdvYU iaeYsTU FsU uysSsU dYmFimSmYU mU cymil,(β∑+ [θ(√(⇒+ θ(⇒+ ′,β+ θβ+ √→](β+ β⇔+ β−β√γ[+ ′,β+
uYvSycsUFveYsUsiUcysYuvíU
Ejercicio #6UUUU 
+ →δ→+⇔→+−,β∑•→+
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→+γ∑→θ⇔→√(⇒+δβ+
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UUUUUUUUUUUUUU U U
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U4[U2TU+T:]UdU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  17  -U
U
UUU→UUUUUUUUUUUU→ U
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23+UU4UδU4[5+TU2TU56]UdU
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32U4UUδUU4UU-U4UUUUUU2UUU+UUUU:UUUUU4U[6TU59TU57]UdíóU
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U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU UU
→U
U 3vYUivUdmodvTUsiUoys vUFaFdsómUlysSmUcvoFdadyaSvUuvYU-U4U
[2TU+TU:]UtonUdYmFimSmSmUmUimU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU UUUUUUU
→U
+ [θ(√(⇒+→∑→⇔β⇔→+′,β+→θ→+[∑+
2UgUsiUóvósodvUSsiU3mYUF32U4U[6TU59TU57]íU
 
1.11   RESULTANTE DE FUERZAS Y MOMENTOS. 
 
U
                              Figura 1.17 (a)                                                 Figura 1.17 (b) 
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U noU imU Ma%yYmU +í+JU *m,U FsU veFsY mU yoU FaFdsómU %sosYmiU SsU MysYtmFTU cvoFdadyaSvU uvYU MysYtmFU gU
óvósodvFUSsUumYsFíUU
U FsSamodsU siU uYvcsSaóasodvU SsFcYadvU soU siU modsYavYUdadyivíU 8asóuYsU sFU uvFaeisU dYmFimSmYU imFU
−,β∑•→θ+→+,⇒→+[θ(√(⇒+→∑→⇔β⇔→+′,β+→θ→+[∑+β⇔+[∑(%soTUve amósodsUdsoasoSvUsoUcysodmUivFUóvósodvFU
cvYYsFuvoSasodsFUgUYscvYSmoSvUlysUivFUóvósodvFUSsUivFUumYsFUFvoU scdvYsFUiaeYsFíU
+ =⇒+⇔→+−(2,∑→++⋅J+]+θβ+γ(β⇒β<+
→UUUUUUUU→UUUUUUUU→UUUUUUUU→ U
-
1U4U-+UHU-2UHU-6U
→UUUUUUUUUU→UUUUUU→UUUUUUUU→UUUUUUU→UUUUUUU→UUUUUU→UUUUUUUUU→UUUUUUUUU→U
F1U4UY+ULU-+UHUY2ULU-2UHUY6ULU-6UHU +UHU 2U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  18  -U
U
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CIERTA CAPACIDAD. 
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Ejercicio #7 
+ →δ[+β⇔+θ(θγβ→+δβ+⇔→+−(2,∑→+⋅ο+δβγβ∑(⇒→∑+⇔→+∑βFyidmodsUSsUóvósodvFíU
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Figura 1.18 
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1U4U[2T52T+]ULU[6TU2T+]UHU[;TU7T9]ULU[5;TU+T6]UHU[:TU:T9]U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  19  -U
U
UU U →U
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Ejercicio #8                         
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU U U U U U U UUUU2UUUUUUUUUUUUUUUUUUUUUU56U
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U U U U U U UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU6UUUUUUUUUUUUUUUUUUUUUUU+U
Solución.- 
UUUUUUUUUUUUUUUUUU→U
m,UUUUUUUUUδ+2U scdvYUSsUSsFuimtmóasodvUU
UUUUU
UUUUUUUUUUU→UUUUUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
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UUUU
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UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUδ+U2UUUUURUUUUδU2U+U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  20  -U
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Ejercicio #9 
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU UUUUUUUUUUUUU U5+UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU →U
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UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU6U
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Solución.- 
U
m,
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UUUUUUU [ ]6T2T+
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r
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e,U1sFuscdvUSsU3
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kji
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4S5<T9T<TUUton_mU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  21  -U
U
Ejercicio #10 UUU
++++++++++++++→δ→+⇔→+−,β∑•→+F
r
⇔[5+TU2TU6U]UdUlysUumFmUuvYUsiUuyodvU
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+−
P
m+βγβ∑(⇒→∑+β⇔+[β⇒γ[+δβ+
F
r
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Solución.- 
m, 1sFuscdvUSsiUvYa%soUU*:TU:T:,UóíU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
U -U
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U F
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U aUUUUrUUUU$U
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U UU
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UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUFu
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UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU6UUU:UUUU6UUUUUUU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  22  -U
U
Ejercicio #11  UUUUUUUUU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU2UUUUUUUUUUUUUUUUUUUU56U
 asYdvUsrsUsFdmUSsMaoaSvUuvYUivFUuyodvFU3
+UUU6U*ó,UUgUUU32UUUU2U 
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UUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU;U
UUUUUUUUU-U⇔[;TU:TU+]UN%UUlysUumFmUuvYUsiUuyodvU3
vUUU52U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU5+U
++βγβ∑(⇒→∑+β⇔+[β⇒γ[+δβ+⇔→+−,β∑•→+∑βθβ√γ[+δβ⇔+βrsíU
Solución.- 
UUUUUUUUUU→U
UUUUUUUUU-UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU:U32UUUUUUUUUUUUUUUUUUUUUUUU3+32U⇔U[57TU5+TU+]U
UUUU3
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UUUUUUUUUδUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU3
+32UUUUU4U7ULU+<U
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U
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UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU7Uí+<U
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2:U⇔U[JTU5;TU52]U
U
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UUUUUU U U ∴F
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Ejercicio #12   
8sUuaSsUSsdsYóaomYUimUYsFyidmodsUóCFUFaóuisUSsiUFaFdsómUm,USsMaoaSvUsoUMvYómUcvuimomYU
UUUUUUUUUUUUU UU -
+U⇔U[6TU52TU:]U0U3 +U*2TU;TU:,U
U U U -
2U⇔U[5+TU5+í7TU:]U0U3 2U*5+TU6TU:,U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  23  -U
U
U
 
Solución.- 
                
→ 
UUUUUUUUUUUUUU U Y +UU⇔U[2TU;TU:]UU
UUUUUUUUUUUUU U
→U
UUUUUUUUUUUUUUUUU U Y 2U⇔U[5+TU6TU:]UUU
 →→→→               U
UF
1UU⇔U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUU
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Y
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UUUUUUUUUUUUUUUUU6UUU52UUUUU:U
UU
→UUUUUUU→ UUUUUUUUaUUUUUUUUrUUUUUU$U
Y
2ULU-2U4UUU5+UUUUUU6UUUUUU:UUUUU4U[:TU:TU;í7]Uton_mU
UUUUUUUUUUUUUUUUU5+UUU5+í7UUUU:U
→U
3mYU4U[:TU:TU;í7]Uton_mU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUUU→UUUUUUU→UUUUUUU→UUUUUU→UUUUUUUU→U
UUUUUUUUUUUUUUUUUUUUUUUF1U4UY+ULU-+UHUY2ULU-2UHU3mYU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
UUUUUUUUUUUUUUUUUUUUUUUF1U4U[:TU:TU5+9]UHU[:TU:TU;í7]UHU[:TU:TU57]U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
UUUUUUUUUUUUUUUUUUUUUUUF1U4U[:TU:TU5+9í7]Uton_mU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
U FvósodvUSsU-
1U⇔UFvósodvUSsiUFaFdsómU
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  24  -U
U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUgU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUU→UUUUUU→U
U Y
1ULU-1U⇔UF 1U
U
U
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UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUF
1U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU(U
U
                                                  →→→→ 
U - 1U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
U 8smU3USsUcvvYSsomSmFU*(TUgTUv,UóUyoUuyodvUSsUimUi'⇒β→+δβ+→√√(⇒+δβ+
1U
U
3U*(TUgTUv,UóU⇒UUY
1UU⇔U[(TUgTUv]U
U
UUUUUUUUU→UUUUUU→UUUUUUUUUUUU→UUUUUUU
UUUUUUUUU(UUUUUgUUUUUvU
⇒UUY
1ULU-1U⇔UF 1U⇒UUUUU52UU56í7UUU:UUUU4U[:TU:TU5+9í7]U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUaUUUUUUrUUUUU$U
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⇔U[:TU:TU56í7U(U52Ug]UUUUUUUUUUULU
+ 3→+β∑βθ(⇒+L+∑β∑βθβ⇒γ→+⇔→+β√,→√(⇒+δβ+,⇒→+∑β√γ→+′,β+δβ−(⇒β+⇔→+⇔ ⇒β→+δβ+→√√(⇒+δβ+⇔→+
YsFyidmodsíU
UU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUU6í7U(UHU2UgU4U+9í7U
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UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
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U
Ejercicio #13UUU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
U5+ 
U "mUMysYtmU-U⇔U[2TU6TU56U]dUUumFmUuvYUsiUuyodvU3 2+++π+++βγβ∑(⇒→∑+β⇔+[β⇒γ[++
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU56U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU:U
SsUSac!mUMysYtmUYsFuscdvUSsiUuyodvU3
+UU52UUU*ó,íUU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU2U
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  25  -U
U
Solución.- 
 
 
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU>U3+UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUUU→UUUUUU→U
U UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUδ +2U4UY2UIUY+U
UUUUUUUUUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUUUUUUUUUU→U
UUUUUUUUUUY+UUUUUUUUUUUUUUUUUUUUUUUUUUUUδ +2UUUUUUUUUUUUUUUUUUUUUUUUUUUUUU-UUUUUUUUUUUY2U4U[? 2TU@2TUA2]U⇔U[5+TU52TU6]U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
→U
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UUUUUUUU>UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU> U
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UU
UUUUUU→UUUUUUUUU5+UUUUU:UUUUU+U
⇒UUFu
+U4UUUU2UUUUU6UUUU56UUUU4U[56TU5+TU56]Uton_mU
UUUUUUUUUUUUUUUUUUUUUaUUUUUUrUUUUUU$U
→UUUUU
→UUUU→UUUUUUUUU→UUUUUU→UUUUUUUUU→UUUUUUUUU→U
F3U4UYULU-U⇔UYULU*- ?UHU-@UHU-A,U
→→→→
     →→→→     →→→→        →→→→     →→→→        →→→→     →→→→ 
MP = r * FX + r * FY + r * FZ      TEOREMA DE VARIGNON 
 
 
U
Ejercicio #14 
UUUUUUUUUUUUUUUUUUUUUUUUU:UUUUUUUUUUUUUUUUUUU56UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU →U
"vFUuyodvFU3+UUU2UU*ó,UgU32UUUU+UUU*ó,USsMaosoUyoUsrsUsoUsiUsFumcavTUyomUMysYtmU-UU
+UUUUUUUUUUUUUUUUUUUU:U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
→U
soUN%íUumFmUuvYUsiUuyodvU3U*6TU2TU5;,íU8sUuaSsUSsdsYóaomYUsiUóvósodvUSsU-U
UUUUUUUUUUUUYsFuscdvUSsiUsrsíU
Solución.- 
 
U UUUUUUUU:UUUUUUUUUUUUUUUUUUUUUU56UUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU6U
3
+UUUU2UUUUUUgUUUUUUU32UUUUU+UUU0UUUU-U⇔U[2TU6TU+]U$%UUU0U3UUUU2UU*ó,UUU
UUUUUUUU+UUUUUUUUUUUUUUUUUUUUUUU:UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU5;U
U
U
∞,[⇒β∑+,⇒→+[∑(β⇒γ→√(⇒<++

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  26  -U
U
U nU
U→
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
3+32U⇔U[*565:,TU*+52,TU*:5+,]U⇔U[56TU5+TU5+]UóUUUU UUU3 2UUUUUUUUUUUUUUUUUUUUUUUUUUUUUU-U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU:UUUUUUUUUUUUUUUUUUU
U→U
U3
+32UUUU⇔U√U6
2
UHU+
2
UHU+
2
U4U6í62UóUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUδUUUUUUUUUUUUvU3U
UU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU3 +vU
U&
nU4UUUUUU+V6í62UUUUUU4U[56TU5+TU+]U4U[5:í<:TU5:í6:TU5:í6:]U
→U
δ3+U3U⇔U[6TU:TU57]U
U
UUUUUUUU→UUUUUUUUUUUUUU→UUUUUUUUUUUUUU→UUUU UUUUUU6UUUUUU:UUUU57U
⇒UF
3+U⇔Uδ 3+U3UULU-U⇔UUUU2UUUUUU6UUUUUU+UUU⇔U[+7TU5+6TU<]U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUaUUUUUUUrUUUUUU$U
U
∴UF
nU⇔U[+7TU5+6TU<]ULU[5:í<:TU5:í6:TU5:í6:]U⇔U[+7L*5:í<:,UHU*5+6,L*5:í6:,UHU<L*5:í6:,]U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU4U[5+6í7UHU6í<U52íJ]UU
UUU U U U U F
nUUU4U5+2í6Ukg_mU
U
EL TEOREMA DE VARIGNON DEMOSTRADO EN EL EJERCICIO A NTERIOR 
ES TAMBIEN VALIDO EN EL CASO DE MOMENTO DE UNA FUER ZA RESPECTO DE 
UN EJE (SE DEJA AL ESTUDIANTE SU DEMOSTRACION). 
Ejercicio #15   
U
→δ[+β⇔+θ(θγβ→+→+√[⇒θγ(γ,(δ[+[∑+δ[θ+−,β∑•→θ+∫+,oUumY0U8sUuaSsUSsdsYóaomYUyoUFaFdsómU
YsFyidmodsUcvoFdadyaSvUuvYUyomUFvimUMysYtmUsoUsiUvYa%soUgUyoUFvivUóvósodvíU
UU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  27  -U
U
Solución.- 
U →U
UUUUUUUUUUU +U3sYdsoscsUmiU3imovU?@U
→UUUUUUUUU→UUUUUUUU→U
-1U4U-+UHU-2U⇔U[+TU;TU+]U
→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
Y+U⇔U[56TU5+TU2]U0UY 2U⇔U[7TU6TU+]U
→UUUUUUUUUUUUU→UUUUUU→UUUUUUUU→UUUUUUU→UUUUUUU→UUUUUUUUUUUUUUUUUUU→UUUUUUUUUUUUUU→U
F1U⇔UY+ULU-+UHUY2ULU-2UHU +UUUU0UUUUUU +UUU4UUUU-UUUULUSU4U2ULU6U4U9Uton_mU
UU U
UUUUUUUUUUUUUUUUUUUUUUUUUUAU
UUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
UUUUU-1UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUF1UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUU→UU UUUUUU56UUU5+UUUU52U
U UUUUU ⇒UUUUY
+ULU-+U4UUUU;UUUU2UUUUUU:UUU4U[;TU5=TU52]U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUaUUUUUUrUUUUUU$U
U
U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU@U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
UUUUUUUUUUUUUUU→UUUUUUU→UUUUUUUUUUUUU 7UUUU6UUUUU+UUUU
U *e,UUUUUUUUUUUUUUUUUUUUUY
2ULU-2U4UUU56UUUU2UUUUU+UUUU4UU[+TU5=TU+<]U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUaUUUUUUrUUUUU$U
U
?UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
→U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU  +U4U[:TU:TU59]U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUF
1U4U[7TU5+9TU++]Uton_mU
U
Ejercicio #16   U
→δ→θ+⇔→θ+φ+−,β∑•→θ+∫+⇔[θ++→∑βθ⋅+G→⇔⇔→∑+,⇒+θ(θγβmUYsFyidmodsíUUUUUUU U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  28  -U
U
→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU56U
-
+U⇔U[2TU:TU;]Ud0UU3 +UUUU5+UUU*ó,U
UUUUUUUUUUUUUUUUUUUUUU52U
→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU2U
-
2U⇔U[7TU5+TU+]Ud0U3 2UU5+UUU*ó,U
UUUUUUUUUUUUUUUUUUUUUUU2U
→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU7U
-
6U⇔U[2TU;TU5+]Ud0U3 6UUU6UUU*ó,U
UUUUUUUUUUUUUUUUUUUUUUU+U
Solucion.- 
→U
+U3sYdsoscsUmiUuimovU@AU
→U
2U3sYdsoscsUmiUuimovU?@U
→UUUUUUUUUUU→UUUUUUUU→UUUUUUUU→U
-1U⇔U-+UHU-2UHU-6U⇔U[<TU6TU;]Ud UU
→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
Y+U⇔U[56TU5+TU52]0UY 2U⇔U[2TU5+TU2]0UY 6U⇔U[7TU6TU+]UU
U
→UUUUUU→U UUUUUUU56UUU5+UUU52U
Y
+ULU-+U4UUUUU2UUUU:UUUUU;UUUU4U[5;TU5=TU2]U
UUUUUUUUUUUUUUUUUUUaUUUUUrUUUUU$U
U
→UUUUUU→U UUUUUUUU2UUU5+UUUU2U
Y
2ULU-2U4UUUUU7UUU5+UUUU+UUUUU4U[+TU=TU6]U
UUUUUUUUUUUUUUUUUUUaUUUUUrUUUUU$U
→UUUUUU→U UUUUUUUU7UUUU6UUUU+U
Y
6ULU-6U4UUUUU2UUUU;UUU5+UUUUU4UU[5JTUJTU+;]U
UUUUUUUUUUUUUUUUUUUaUUUUUrUUUUU$U
U
→UUUUUUUUUU→UUUUUU→UUUUUUUU→UUUUUU→UUUUUUUU→UUUUUU→UUUUUUUU→UUUUUUUU→U
F1U4UY+ULU-+UHUY2ULU-2UHUY6ULU-6UHU +UHU 2U
UUUUUUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
U⇒UU +UUU4U7ULU;U4U2:UUU0UUUUU +U4U[2:TU:TU:]UU
U
UUUUUUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
U⇒UU 2UUU4U;ULU2U4U=UUUU0UUUUU 2U4U[:TU:TU5=]UU
UUUUUUUUUUUUUUU→U
UUU∴UUUF1U4U[+:TUJTU++]Uton_mU
U
Ejercicio #17    
→δ→+⇔→+−,β∑•→+
F
r
U4U[6TU52TU;]+β⇒+γ[⇒β⇔→δ→θω+θβ+(δβ+δβγβ∑(⇒→∑<+
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  29  -U
U
Solución.- 
U m,U vóuvosodsFUsFcmimYsFU⇔U6UdTU52UdTU;UdU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
→UUUUUUUUUU→UUUUUUUU→U
U e,U vóuvosodsFU scdvYamisFU⇔U6UaUTU5U2UrUTU;U$U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
→U
U c,UFm%oadySUSsU-U4U ( )
222
;26 +−+ U4U7í6=UdU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUU→UU→U
+ δ+β√γ[∑+,⇒(γ→∑([+β⇒+⇔→+δ(∑β√√(⇒+δβ++⇔U sU-U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
→UU→UUUUUUUUUUUUUUUU
U U U
sU-U4UUUUUUUU
+
UUUUUUULU[6TU52TU;]U4U[:í77TU5:í6JTU:íJ;]UUUU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU7í6=U
U
+ β+{θβ⇒[θ+δ(∑β√γ[∑βθ<+
U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU6UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU52UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU;U
U UUUUUUUUUUUcvFUαU4UUUUUUUUUUUU4U:í77UUUUcvFUβU4UUUUUUUUUUUU4U5U:í6JUUUcvFUγU4UUUUUUUUUUUUU4U:íJ;UUUUUUUUUU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU7í6=UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU7í6=UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU7í6=UUU
U
U
Ejercicio #18    
→δ[θ+⇔[θ+,⇒γ[θ++U*2TU56TU5;,UgU32+⌠ω+ϖω+πω+β⇒+βγ∑[θω+θβ+(δβ<+
Solución.- 
U
+ →+β√γ[∑βθ+δβ+[θ(√(⇒+δβ+
+UgU32UU
U U U U
→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
U U U U Y +U4U[2TU56TU5;]Uó0UY 2U4U[:TU7TU5+]UUUUUUU
U
U e,U/scdvYUSsUSsFuimtmóasodvUsodYsU3
+UgU32U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUU→UUUUUU→U
U U U δU4UY 2UIUY+U4U[:UIU2í7UIU*56,TU5+UIU*5U;,]U4U[52TU=TU6]UóU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
UUUUUUUUUUUUUUUUUU→U
+ √+(θγ→⇒√(→+β⇒γ∑β++UgU32U⇔UUUUUδU
U
UUUUUU→U
U U UUUUUUUUUUUUUUδUUU4U ( )
222
6=2 ++− U4U=íJJUóU
U
Ejercicio #19U
→δ[+β⇔+,⇒γ[+ω+φω+πϖ+ω+∫+⇔→+−,β∑•→+
+U4U[:TU5;TU6]UdTUlysUumFmUuvYUsiUuyodvU3 2U*9TU5;TU2,UóTU
θβ+(δβ<+
Solución.- 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  30  -U
U
U
U m,UFvósodvUSsU-
+UYsFuscdvUSsiUvYa%soU>U*:TU:TU:,UU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUU
→U
U U U >3 2U4U[9TU5;TU2]U⇔UYU⇔+)β√γ[∑+δβ+[θ(√(⇒+δβ+ 2U
UUUUUUUUUUUUUUUUUUUUUUUU→UUUUU
→UUU→UUUUUUUU9UUU5U;UUUU2U
U U F
>U4UYULU-+U4UUUU:UUU5U;UUUU6UU4U[5U;TU5U+=TU5U2;]Uton_mU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUaUUUUUUrUUUUU$U
U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
U U Fm%oadySUSsUF
>U⇔UUUF>UUUUU4U6:í29Uton_mU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
U→U
U e,UFvósodvUSsU- +UYsFuscdvUSsU3+U
UUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUU→U
U U 3 +32U4U[;TU5JTUJ]U⇔UδU⇔U scdvYUSsUSsFuimtmóasodvUSsU3 +UmU32U
U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU;UUUU5UJUUUUJU
U U F
3+U4UδULU-+U4UUU:UUUU5U;UUUU6UUUU4U[JTU5U+2TU5U+9]Uton_mU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUaUUUUUUUrUUUUU$UUUUU
[⇒δβ<+++++++++++++→UUUUUUUU
→U
U U F ?U4UJUaU
U U →UUUUUUUUUU
→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
U U F
@U4U+2UrUUUUUUUUUUUUU vóuvosodsFU scdvYamisFUSsUFu+U
UUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUUUUUUU
→U
U U F AU4U5U+9U$U
∆δβ∴θ<+F→2⇒(γ,δ+δβ+F
+U4UUUFu+UUUU4U2+í+<Uton_mU U
U
Ejercicio #20     U
++++++→δ[θ+⇔[θ+,⇒γ[θ+
+U*2TU:TU6,UóUgU32U*5;TU7TU:,UóUlysUSsMaosoUyoUsrsUgUimUMysYtmU
F
r
4U[7TU9TU52]UdU
lysUumFmUuvYU3
6+⌠ω+πω++ω+θβ+(δβ<+
U
Solución.- 
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
→U
U m,UFvósodvUSsU-UYsFuscdvUSsiUsrsU⇔UF nU
U U UUUUUUUUUUUUU→UUUUUU
→U
U U U 3 +36U4UδU4U[52TU52TU52]UóUUUUUUUUUUUUUUUUUUUUUUUU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUU
→U
U U U 3 236U4Uδ+U4U[;TU5JTU+]+++++++++β⇒γ[⇒√βθ<+++
UUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUU
→UUU→UUUUU5U2UUUU5U2UUUUU5U2U
U U Fu
+U4UδULU-U4UUUUU7UUUUUUU9UUUUU52UUU4U[+9TU5U+;TU5U2]Uton_mU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUaUUUUUUUrUUUUUUUU$UU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  31  -U
U
U
U UUUUUUUUUUUU→UUUUUUU
→UUU→UUUUUUUU;UUUU5UJUUUUUU+U
U U Fu
2U4UδULU-U4UUUUU7UUUUUU9UUUUU52UUUU4U[=TU+6TU7<]Uton_mU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUaUUUUUUUrUUUUUUU$UU
UUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
∆δβ∴θ<++32U4U[59TU7TU56]U⇒UU3 +32UUU4U=í6JUóTUuvYUdmodv0UsUnU4U[5:íJ2TU:í9TU5:í69]UU
β⇒γ[⇒√βθ<
UUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUUUUUU→ U
U U F
nU4UFu+ULUsnUUUUUUUvUeasoUUUUUFnU4UFu2ULUsnU
U
=θ+δβ√(∑<+
F
nU4U[+9TU5+;TU52]ULU[5:íJ2TU:í9TU5:í69]U4U5U+<í2Uton_mU
vUeasoUU
F
nU4U[=TU+6TU7<]ULU[5:íJ2TU:í9TU:í69]U4U5U+<í2Uton_mUU UUUU
U
Ejercicio #21   
{[⇒+⇔[θ+δ→γ[θ+δβ⇔+→⇒γβ∑([∑+βαβ⇔[+θβ+(δβ<+
Solución.- 
U m,UFvósodvUSsU-UYsFuscdvUmUdYsFUsrsFUvYdv%vomisFUcvocyYYsodsFUsoU3 +UgUmUivFUsrsFUcmYdsFamovFU
⇔UF
nWn8UUUUUUUUUUUUUUUUUUUUUU→UFu +U4U[+9TU5U+;TU52]U
U U U F
nWnU?U4U[+9TU:TU:]ULU[aTU:TU:]U4U+9UUton_mU
U U U F
nWnU@U4U[:TU5+;TU:]ULU[:TUrTU:]U4U5+;UUton_mU
U U U F
nWnUAU4U[:TU:TU52]ULU[:TU:TU$]U4U5U2UUton_mU
U 8sUovdmUmSsóCF0UlysUsiUóvósodvUSsUyomUMysYtmUYsFuscdvUSsUyoUuyodvTUsFUa%ymiUmUimUFyómUSsU
ivFUóvósodvFUSsUSac!mUMysYtmTUYsFuscdvUSsUdYsFUsrsF+[∑γ[2[⇒→⇔βθ+′,β+→θ→⇒+[∑+β⇔+,⇒γ[+βθ+δβ√(∑<+
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUU→UUUUUUUUUU→UUUUUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
U U U F
3+U4UFnWnU?UHUFnWnU@UHUFnWnUAU4U[+9TU5U+;TU5U2]UUUton_mU
U
U
U
1.12   PROBLEMAS PROPUESTOS. 
U
Problema #1  
U →UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
-U4U[6TU;TU52]+γ+∫++ω+⌠ω+πφ++,⇒+,⇒γ[+δβ+⇔→+⇔ ⇒β→+δβ+→√√(⇒+SsU-TUmSsóCFUyoUuyodvUmYeadYmYavU
3
++ϖω+πφω+π++∞β+(δβ<+
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
m,UFvósodvUSsU-UYsFuscdvUSsiUvYa%soíU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  32  -U
U
UUUUUUUUUUUUUUUUUUUUUUUUUU→U
e,UFvósodvUSsU-UYsFuscdvUSsU3+U
Respuesta<+→+F
>U4U[+2TU5+TU+9]Uton_mTUe,UFu +U4U2UaUIU=UrUIU+6U$Uton_mU
U
Problema #2U
U
"vFUSsiUsrsYcacavU+í+UgUsiUuyodvUmYeadYmYavU3
2+⌠ω+ω+π++∞β+(δβ<+
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
m,UFvósodvUSsU-UYsFuscdvUSsiUsrsU3+U32íU
U
Respuesta:Um,UF nU4U5U92+Uton_mU
 
 
Problema #3
 
→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
-U4U[56TU7TU:]+γ+∫++⌠ω+ω+++,⇒+,⇒γ[+δβ+⇔→+⇔ ⇒β→+δβ+→√√(⇒+δsU-TUmSsóCFUyoUuyodvUmYeadYmYavU
3
++ω+φω+π++∞β+(δβ<+
U
m,
 FvósodvUSsU-UYsFuscdvUmUdYsFUsrsFUvYdv%vomisFUcvocyYYsodsFUsoU3 +UgUumYmisivFUUmUivFUsrsFU
cmYdsFamovFíU
U
Respuesta<
 a)UF(U4U527Uton_m0UF gU4U5+7Uton_m0UF tU4U5+6Uton_mU
 
Problema #4 
UUU
β[θγ∑→∑+β⇔+γβ[∑β→+δβ+→∑(2⇒[⇒ω+→∑→+β⇔+√→θ[+δβ⇔+óvósodvUSsUyomUMysYtmUYsFuscdvUSsUyoU
uyodvíU
U
Problema #5 
→∑→+⇔→+θ(2,(β⇒γβ+−(2,∑→+θβ+(δβ+δβγβ∑(⇒→∑<+
m,U"vFUóvósodvFUSsUivFUumYsFU 
+TU 2UgU 6íU
e,U"mUFyómUSsUivFUóvósodvFUSsUivFUumYsFU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  33  -U
U
U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUUUUUUUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→UUUUUUUUUU→UUUUUUUUUU→U
Respuesta<+→+F +U4U9Ur0UF2U4U5Jí7Ua0UF6U4U;U$UsoUton_mTU b)UF+UHUF2UHUF6U4U[5Jí7TU9TU;]Uton_mU
U
Problema #6  
{[⇒+⇔[θ+δ→γ[θ+δβ⇔+∑[]⇔β→+φ+θβ+(δβ<+
UUUUUUUUUUUUUUUUUUUU
→U
→+P∑→θ⇔→δ→∑++→+,⇒→+[θ(√(⇒+→∑→⇔β⇔→+′,β+→θβ+[∑U3 +íU
]+⇒δ(√→∑+⇔→+√[[θ(√(⇒+δβ⇔+⇒,β)[+θ(θγβ→⋅+
UUUUUUUUUUUUUUUUUU→UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
Respuesta<+→ )U-UdYmFimSmUmU3+UsoUMvYómUumYmisimTUb)U-UsoU3+UómFUFu+4U[527TU5+7TU5+6]Uton_mU
 
Problema #7
 
++++++++++++=⇔+θ(θγβ→+δβ+⇔→+−(2,∑→<+
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  34  -U
U
∞β+(δβ<+→+βθ,⇔γ→⇒γβ+δβ+−,β∑•→θ+β⇒+β⇔+[∑(2β⇒⋅+
UUUUUUUUUUUUUUUe,U1sFyidmodsUSsUóvósodvFíUU
Respuesta:Um,U-
1U4U[;TUJTU<]UdTU b)UF1U4U[59TU9TU+;]Uton_mU
Problema #8U
noUsiUFaFdsómUcvuimomYUSsUimUMa%yYmUU
U
∞β+(δβ<++
UUUUUUUUUUUUUUm,U1sFyidmodsUSsiUFaFdsómíU
+ ++]+3 ⇒β→+δβ+→√√(⇒+δβ+⇔→+∑βθ,⇔γ→⇒γβ⋅+
UUUUUUUUUUUUUUUUUUUUUUUU
→U
Respuesta: a)U-1U4U[6TUJTU:]UdTU b)UFs%#oUimUYscdmUJ(UIU6gU4U=U
U
U
Problema #9   
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
UUUUUUUUUUUUUniUFaFdsómUcvuimomYUSsUimUMa%yYmU
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  35  -U
U
∞β+(δβ<++
m,
 1sFyidmodsUSsiUFaFdsómíU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU→U
Respuesta<  a)UsiUumYUF>U4U[:TU:TU+]Uton_mU
U
U
1.13  EVALUACION DIAGNOSTICO DEL CAPITULO. 
 
 
noUsFdsUmumYdmSvUFsUuYvuvosUlysUsiUsFdySamodsUYsmia√β+,⇒→+β)→⇔,→√(⇒+δβ+γ[δ[+⇔[+→∑β⇒δ(δ[+β⇒+
sFdsUcmuadyivTUumYmUivUcymiUFsUoscsFadmUlysUYsFuvoSmUimFUFa%yasodsFUuYs%yodmFUFaoUYs aFmYUsiUcvodsoaSvU
SsiUuYsFsodsUcmuadyivíU
U  vóvUFsUsocysodYmUsiUSsFuimtmóasodvUSsUyoUuyodvUYsFuscdvUSsiUvYa%soXU
U QysUsFUimUóm%oadySUSsUyoU scdvYXU
U β−(⇒(β⇒δ[+⇔→+→2⇒(γ,δω+√[[+θβ+β⇒√,β⇒γ∑→+⇔→+δ(θγ→⇒camUsodYsUsiUvYa%soUgUyoUuyodvXU
U  vóvUFsUSsMaosUsiUóvósodvUSsUyomUMysYtmUcvoUYsFuscdvUmUyoUuyodvXU
U β[θγ∑→∑+β⇔+γβ[∑β→+δβ+VARIGNON YsFuscdvUSsUyoUsrsíU
U β−(⇒(∑+′,β+βθ+,⇒+→∑+δβ+−,β∑•→θ⋅+
3mYmUcvociyaYUsFdsUSam%ovFdacvUFsUuaSsU!miimYUimUYsFyidmodsUSsiUFa%yasodsUFaFdsómUSsUMysYtmFíU
U
U
U
íU
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  36  -U
U
 
 
 
CAPÍTULO 2 
  
INTRODUCCION AL ANÁLISIS DE LAS 
ESTRUCTURAS 
U
 
 
2.1   OBJETIVO GENERAL. 
niUversda vUMyoSmósodmiUSsUsFdsUcmuadyivUsFU!mcsYUlysUsiUsFdySamodsUcvovtcmUsiUcvocsudvUSsU
642A(m2(A+  m3S3  2+S7oI-  .34  )o16A6-264  2oP34  )6  m+A%mFU gU muvgvFU lysU mcd#moU soU yoU FaFdsómU
sFdYycdyYmiíU
2.2   OBJETIVOS ESPECIFICOS. 
  e. 26ASo-+A 6. m+Po2(.3 6. 642()o+-26 P3)ABa 
U l.+4o1om+AB .+4 642A(m2(A+4 P3A 4( 13AS+ v63SI2Aom+TUuvYUFyUFaFdsómUSsUcmY%mFTUuvYUFyUFaFdsómUSsU
muvgvFUgUuvYUFyFUcvoSacavosFUSsUaFvFdmdacaSmSíUU
U d626ASo-+A+ .+4 A64(.2+-264 )6 m+Av+4 )o42Ao7(o)+4 i .+ P34omof- 6- .+ =(6 642+ +m2M+n 
U d626ASo-+A+  .+4  A6+mmo3-64  )6  +P3i3  )6  )o42o-234  2oP34  )6  642A(m2(A+4  *yov+4L  PfA2om34L  +Am34L 
sFdYycdyYmFUóa(dmF,íU
2.3UUINTRODUCCION.U
l3- (- A+t3-+So6-23 .fvom3 i 3A)6-+)3 46 .6 PA3P3AmavomUmiUiscdvYUivFUsisósodvFUSsUmoCiaFaFU
P+A+ =(6L + P+A2oA )6 .+ )61o-omof- )6. m3-m6P23 )6UsFdYycdyYm0UimFUcimFaMalys0USsUimUóaFómUMvYómUuvYU
4(4 m3-)omo3-64 )6 o4342+2omo)+)L o)6-2o1om+-)3 +a imFUsFdYycdyYmFU!auvFdCdacmFU*aosFdmeisF,TUcymoSvUsiU
-MS6A3 )6 .+4 o-mfv-o2+4 )6. 4o426S+ 64 S6-3A + .+4UcvoSacavosFUSsiUslyaiaeYavUsFdCdacv0UsFdYycdyYmFU
o4342B2om+4  *642+7.64C  m(+-)3  6.  -MS6A3  )6  .+4  o-mf%oadmFU SsiU FaFdsómU sFU a%ymiU miU o#ósYvU SsU imFU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  37  -U
U
scymcavosFUSsUslyaiaeYavUsFdCdacv0UsFdYycdyYmFU!ausA642B2om+4L m(+-)3 6. -MS6A3 )6 .+4 o-mfv-o2+4 64 
ómgvYUmiUo#ósYvUSsUimFUscymcavosFUSsiUslyaiaeYavUsFdCdacvíUU
U
2.4   CONCEPTOS BÁSICOS Y DEFINICIONES.  
d(A+-26 6. PA3m643 )6 13AS+mof- )6. o-v6-o6A3 moyo.TUsiUcvocsudvUSsUsFdYycdyYmUFsUsocysodYmU
YsMsYaSvUmUyoUcvoryodvUSsUsisósodvFUlysUimUcvoMvYóm-0 6SP6A3L I42+ +46y6A+mof- -3 )6S(642A+ (-+ 
)61o-omof- P+A+ 6-26-)6A.3 6- 23)+ .+ 6826-4of- )6 FyUFa%oaMacmSvíU3vYUsoSsTUmiUuimodsmYFsUimUuYs%yodmU
SsUlysUsFUyomUsFdYycdyYmTUimUYsFuysFdmUuysSsUSmYFsUyoUdmodvUFyersda míU3vYUivUlysTUumYmUsodsoSsYivUgU
mFaóaimYivUsFUoscsFmYavUcvoFaSsYmYUcvóvUuYsóaFmUsiUsodvYovUlysUimUYvSsmíUU
8o 2(yoIA+S34 m(Ao34o)+) )6 46A 3746Ay+)3A64 26-o6-SvU#oacmósodsUoysFdYvUósSavUmóeasodsU
cvóvUi'óadsTUvUsoUvdYmFUumimeYmFTUsiUi'óadsUSsUoysFdYmU aFdmUgUYmtvomóasodv0UovFUSmY'móvFUcysodmUlysU
uvSsóvFU aSsodaMacmYU SaMsYsodsFU sFdYycdyYmFTU SaMsYsomoB-)3.+4  P3A  4(  (2o.ot+mof-  P+A+  .3  =(6  1(6A3- 
SaFsCmSmF0U mF'TU soU siU CóeadvU casod'MacvU SsU imU ao%soo6Ab+  moyo.L  6-  13AS+  -+2(A+.  )o4mAoSo-+Ab+S34a 
 mFmFU !meadmcavosFTU sSaMacavFU SsU vMacaomFTU sFcysimFTU uysodsFTU dmolysFTU sSaMacavFU SsumYdmósodmisFTU
moyocavFUsFuscdmcyimYsFTUmsYvuysYdvFTUuYsFmFTUSaFdYadvUSsUYas%vTUcmYYsdsYmFTUmicmodmYaiimSvTUi'osmFUSsU
m3-)(mmof-  i  )o42Ao7(mof-  )6  +v(+  P32+7.6L  6-2A6  32A+4L  23)+4  6..+4  m(SP.o6-)3  (-  PA3Pf4o23 
umYdacyimYUumYmUivUlysUMysYvoUSaFsCmSmFíU U
33A .3 2+-23a  
U
U ESTRUCTURA, ES UN CONJUNTO DE ELEMENTOS CON FORMA G EOMÉTRICA 
QUE, UNIDOS ENTRE SÍ POR MEDIO DE NODOS, SOPORTAN C ARGAS QUE SON 
TRANSMITIDAS  A  SUS  APOYOS  A  TRAVÉS  DE  LOS  ELEMENTOS  
ESTRUCTURALES QUE LA INTEGRAN.  
U APOYO, ES UN DISPOSITIVO CONSTRUCTIVO QUE PERMITE E NLAZAR ENTRE 
SI LOS ELEMENTOS ESTRUCTURALES Y/O SUJECIÓN ENTRE L A ESTRUCTURA 
Y EL SISTEMA TIERRA, CON EL PROPÓSITO DE EVITAR DES PLAZAMIENTOS. 
d6 46A +m6P2+)+ .+ )61o-omof-L 6. m3-5(-23 )6 6.6S6odvFUlysUaods%YmoUyomUsFdYycdyYmUSsesUSsU
m3-26-6A  4oS(.2B-6+S6-26a  13AS+  v63SI2Aom+L  4o426S+U SsU cmY%mFU gU FaFdsómU SsU muvgvFTU YsMsYsocamFU
lysUMmcaiadmoUdsosYUsisósodvFUSsUmoCiaFaFUumYmUuimo26+A (-+ m.+4o1om+mof- 6- 1(-mof- )6 4( v63S62Ab+L 
SsUFyFUmuvgvFUgUSsUFyFUcmY%mFíU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  38  -U
U
2.5  TIPOS DE ESTRUCTURAS. 
c+  m.+4o1om+mof- 6- 6. 6-23A-3 )6 .+4 642A(m2(A+4L 46 )+ 6- 1(-mof- )6 .+ (7om+mof- )6 4(4 
sisósodvFTUlysUuysSsoUsFdmYUivcmiatmSvFUsoUsiUuimovUvUsoUsiUsFumcav0UsoUcvoFscysocamTUimFUsFdYycdyYmFU
46 )oyo)6- 6-a 
2.5.1 Estructuras planas. 
8voUmlysiimFUcymoSvUFyFUsisósodvFUFsUsocysodYmoUsoU(- P.+-30 (-+ A6PA646-2+mof- )6 I42+4 46 
srsóuiaMacmUaSsmiatmoSvUyomU a%mUFaóuisósodsUmuvgmSmUlysUFsUsocysodYmUivcmiatmSmUFveYsUsiUuimovU
?@TUcvóvUFsUóysFdYmUsoUimUMa%yYmU2í+UcvoUimUemYYmUIEíU
U
Figura 2.1 
2.5.2 Estructuras en el espacio. 
8sUaSsodaMacmoUcvóvUdmisFUcymoSvUmiUósovFTUyovUSsUFyFUsisósodvFUFsUsocysodYmUsoUsiUsFumcavíU
8aUFsUveFsY mUimUMa%yYmU2í2TUsiUómYcvUIE5>nUFsUsocy6-2A+ 6- 6. P.+-3 ?@0 i P6AP6-)om(.+A + I426L 
FveYsUsiUsrsUAUFsUyeacmUsiUómYcvUYG5N"UYsFyidmoSvUsoUcvoFscysocamUyomUsFdYycdyYmUsoUsiUsFumcavíU
PvómoSvUSsUYsMsYsocamUsiUmicmocsUlysUFsUuYsdsoSsUsoUsiUmoCiaFaFUSsUimFUsFdYycdyYmFUaFvFdCdacmFTU
FsUmevYSmoU#oacmósodsUimFUsFdYycdyYmFUuimomF0UaSsodo1om+-)3 6-2A6 6..+4 .+ 4ov(o6-26 m.+4o1om+mof-a
 
U
Figura 2.2 
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  39  -U
U
2.6 CLASIFICACION DE LAS ESTRUCTURAS 
 
 
"mF cFóvEpEcódYnjv tjd vr pjdnó  5Yjn2XdEcóf tjd vr vEvXsómUSsU muvgvFTU uvYUFyUFaFdsómUSsU
cmY%mFíU
U
2.7 POR SU FORMA GEOMÉTRICA. U
)óv YvXdrcXrdóv tjd vr pjdnó 5Yjn2XdEcó Ye YF cjeXY(dvUSsUFyFUsisósodvFUlysUimFUaods%YmoUFsU
cimFaMacmoUsoUYscdmFTUcyY mFUgUSsUcvodmcdv0UumYmUFy EsYeXEpEcócE3e vY EesEcódle Ye óF5reóv Fóv cód5óv gU
ótjujv beEcónYeXY tódó vr EsYeXEpEcócE3ef uó orY tódó vr sYpEeEcE3e vY Y7tjeYe Ye Fóv vE5rEYeXYv 
vYccEjeYv sY 2vXY cótyXrFjz  
2.7.1 Viga  Horizontal. "mU Ma%yYmU YsuYsFsodmU yomU  a%mU FaóuisósodsU muvgmSmU cvoU cmY%mU
cvocsodYmSmUZ3ZUgUyomUcmY%mUyoaMvYósósodsUSaFdYaeyaSmUZ[Zí* sYUMa%í2í6,íU
U
Figura 2.3 
 
2.7.2 Viga Inclinada. "mUMa%yYmU2í9UYsuYsFsodmUmUyomU a%mUFaóuisósodsUmuvgmSmUcvoUcmY%mU
cvocsodYmSmTUveFsY moSvUlysUimUemYYmUIEUdasosUyomUSEdYccE3e dYvtYcXj óF YZY (jdEajeXóF Ye 
precE3e sYF le5rFj \ 
U
Figura 2.4 
 
2.7.3 Columnas.  nFUyoUsisósodvUsFdYycdyYmiU sYdacmiUvUaociaomSvíU voUimUMa%yYmU2í7UlysUFsU
óysFdYmUFsUsFlysómdatmUyomUcviyóomU sYdacmiUIEUcvoUcmY%mUcvocsodYmSmUm(amiíU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  40  -U
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U
Figura 2.5 
 
2.7.4 Marcos  o  Pórticos. nFdCoU cvoFdadyaSvFU uvYU yoU cvoryodvU SsU sisósodvFU Yscdai'osvFTU
!vYatvodmisFTU  sYdacmisFU gVvU aociaomSvFíU nisósodvFUlysU FvuvYdmoU cmY%mFU cvocsodYmSmFU vU
SaFdYaeyaSmFUcvóvUFsUóysFdYmUsoUimFUFa%yasodsFUMa%yYmFíU
U
Fig 2.6 (a)                              Fig 2.6 (b)  
2.7.5 Armaduras.  "mFU aods%YmoU yoU cvoryodvU SsU sisósodvFU Yscdai'osvFU Ysimda mósodsU
sFesidvFU lysU sFdCU yoaSvFU Y'%aSmósodsU soU FyFU s(dYsóvFU lysU FvuvYdmoU cmY%mFU cvocsodYmSmFU
SaYscdmósodsUFveYsUimFUyoavosFUvUovSvFUcvóvUFsUóysFdYmUsoUimUMa%yYm

U
Figura 2.7 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  41  -U
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2.7.6 Arcos.  nFdCoU aods%YmSmFU uvYU yoU cvoryodvU SsU sisósodvFU cyY vFU SsU MvYómU caYcyimYTU
YFytXEcó j tódói3FEcóz gF dYvtYcXj vY nrYvXdóe Fóv vE5rEYeXYv pE5rdóv1 
 
Fig 2.8 (a)                          Fig 2.8 (b)  
2.7.7 Cables.  :YcXEFyeYjv  Ye  crujv  treXjv  sY  EepFY7E3e  vjtjdXóe  cmY%mFU cvocsodYmSmFíU
Sódói3FEcjv orY vjtjdXóe cód5óv dYtódXEsóvf 4óiFYv lysUFvuvYdmoUFyUusFvUuYvuavíUUU
 
Fig 2.9 (a)                          Fig 2.9 (b)  
U
Fig 2.9 (c) 
2.8 POR SU SISTEMA DE APOYOS 
¿QUE ES UN APOYO? 
 vóvUgmU!me'móvFUósocavomSvUyoUmuvgvUsFUyoUSaFuvFada vUcvoFdYycda vUlysUusYóadsUsoimtmYU
YeXdY  vE  Fjv  YFYnYeXjv  YvXdrcXrdóFYv  uVj  vrZYcE3e  YodYsU imU sFdYycdyYmU gU siU FaFdsómU dasYYmTU cvoU siU
tdjt3vEXj sY YxEXód sYvtFóaónEYeXjvz  

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  42  -U
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nFdvFUmuvgvFUdasosoUuvYUversdvUYsFdYao%aYUivFUSsFuimtmóasodvFUsoUmi%yovUSsUivFUsrsFUsoUivFUlysU
sFdsUyeacmSvTUgUFs%#oUmUivFUdauvFUSsUmuvgvUcvoUimFUYsFdYaccavosFUYsFuscda mFUimFUcimFaMacmYsóvFUsoUsiU
tFóej sY Fó vE5rEYeXY nóeYdó1 
Tabla 2.1 Sistemas de apoyosU
Nombre del apoyo Vínculos  Grados de libertad  diagrama 
,3xEF  6ej  .jv 
U
_EZj  .jv  6ej 
U
nóuvdYmóasodvU PYsFU  sYvU
U
Yryó  .jv  6ej 
U
U U
Sódó Fó nYZjd cjecYtcE3e sYF vYeXEsj sY Fóv dYóccEjosFUSsUmuvgvUsoUsiUuimovUuYvuvosóvFUimU
vE5rEYeXY XóiFó1 
Tabla 2.2   Grados de libertad en apoyosU
Esquema  Nombre  Grados de libertad  Diagrama 
U
,3xEF  .jv 
RY
U
U
-arvU &ovU
R
Y
U
U
nóuvdYmóasodvU  sYvU
M
R
Y
Z
U
U
Yy'mU &ovU
M
R
X
Z
U
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  43  -U
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2.9 POR SU SISTEMA DE CARGAS 
 
r-+ PAoS6A+ m.+4o1om+mof- )6 .+4 642A(m2(A+4 P3A 4( 4o426S+ )6 m+Av+4 46 o)6-2o1om+-a 
U c+4 m+Av+4 6826A-+4a +m2M+- 437A6 .+ 4(P6A1omo6 )6.UsisósodvUsFdYycdyYmiíU
U c+4 m+Av+4 o-26A-+4a +m2M+- )6-2A3 )6. 6.6S6-23 642YycdyYmiU*cvóvUsFUsiUcmFvUSsUivFU
sisósodvFUóscCoacvFUlysUFsUmomiatmoUsoUsiUFa%yasodsUcmuadyiv,U
 voU emFsU soU ivU modsYavYTU cymoSvU imU sFdYycdyYmU FvuvYdmU yoU FaFdsómU SsU cmY%mFU s(dsYovU FsU
o)6-2o1om+-a 33A 6. 2oP3 )6 m+Av+L P3A 4( P6AS+-6-mamUgUuvYUimUMvYómUsoUlysUmcd#míU
U
2.9.1 Por el tipo de carga. 
2.9.1.1   Cargas concentradas. 
83- +=(6..+4 =(6 2o6-6- (- 43.3 P(-23 )6 +P.om+mof-U
2.9.1.2   Cargas Axiales.  83- +=(6..+4 =(6 642B- +m2(+-)3 6- 6. m6-2A3 v63SI2YacvUSsU
(-+ 46mmof- 2A+-4y6A4+.n 
U
Figura 2.10 
2.9.1.3  UUCargas no axiales. 83- +=(6..+4 =(6 +m2M+- 1(6A+ )6. m6-2A3 v63SI2AomvUSsU
(-+ 46mmof- 2A+-4y6A4+.L v6-6A+-)3 (-+ 68m6-2Aomo)+SU*s,íU sYUMa%U2í++U
U
U
Figura 2.11 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  44  -U
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2.9.1.4   Cargas  distribuidas.  )ó  xódEócE3e  sY  Fó  cód5ó  Yv  cjevXóeXY  vjidY  YF  cFóYvU
"L" sjesY YvXó ócXróesj cjnj vY jivYdxó Ye Fó pE5rdó1U
U
Figura 2.12 
 
2.9.1.5   Carga no uniforme. )ó xódEócE3e sY Fó cód5ó ej Yv cjevXóeXY vjidY YF cimYvU
"L"USvoSsUsFdmUmcdymoSvíU3vYUsrsóuivTUsoUimUMa%yYmUlysUFsUóysFdYmUFsUSaFdao%ysUyomUcmY%mUSsU
xódEócE3e FEeYóF vjidY YF Xdónj 
"a" u cje reó xódEócE3e crósdlXEcó vjidY YF Xdónj "b"íU
U
Figura 2.13 
2.9.2 Por  su  permanencia.  8sU cimFaMacmoU soU cmY%mFU  a mFTU cmY%mFU óysYdmFU gU cmY%mFU
mccaSsodmisFíU
2.9.2.1 Cargas vivas.  Sódó reó vEntFY EsYeXEpEcócE3e u re XóeXj cjFjorEóiTUFsUSsMaosoU
cjnj  óorYFFóv  orY  vY  nrYxYeR  tjd  YZYntFj  Ye  re  vóF3oU SsU cimFsFU imU cmY%mU  a mU sFdmU
YsuYsFsodmSmU uvYU siU usFvU SsU ivFU miyóovFU lysU FsU s(uYsFmoU soU yoaSmSsFU SsU ivo%adySU miU
cymSYmSvíU
2.9.2.2 Cargas  muertas. U nFdCoU YsuYsFsodmSmFU uvYU siU usFvU uYvuavU SsiU sisósodvU
sFdYycdyYmiU
2.9.2.3 Cargas  accidentales.U 8voU mlysiimFU lysU sFdCoU YsuYsFsodmSmFU uvYU imU MysYtmU
F'FóacmTUuvYUimUMysYtmUSsiU asodvTUuvYUsiUusFvUSsUimUoas sTUsdcíU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  45  -U
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2.9.3 Por la forma en que actúan.U
8voUimFUcmY%mFUmcda mFTUimFUcmY%mFUYsmcda mFUgUimFUcmY%mFUaodsYomFí* sYUMa%yYmU2í+;,
 
U
Figura 2.14 
2.9.3.1 Cargas activas. nFdCoUYsuYsFsodmSmFUuvYUsiUFaFdsómUSsUcmY%mFUs(dsYovU*gU4Uó(0U
gU4Uó(],UlysUsFdCoUmcdymoSvUFveYsUsiUsisósodvUsFdYycdyYmií
 
2.9.3.2 Cargas reactivas. 
nFdCoUYsuYsFsodmSmFUuvYUimFUcvóuvosodsFUSsUcmSmUyovUSsU
ivFU muvgvFU lysU FvuvYdmoU miU sisósodvU sFdYycdyYmiU *1I+ E+ (δβ⇒γ(−(√∴⇒δ[θβ+ γ→](⇒+ √[[+
 'ocyivFUvUYsmccavosFíU
2.9.3.3 Cargas internas.U8voUimFUlysUmcd#moUSsodYvUSsiUsisósodvUsFdYycdyYmiTUóaFómFU
′,β+θβ+[[⇒β⇒+→+⇔→+→√√(⇒+δβ+⇔→θ+√→∑2→θ+βγβ∑⇒→θ⋅+β⇒γ∑[+δβ+θγ→+√⇔→θ(−(√→√(⇒+θβ+δ(θγ(⇒2,β⇒<+
"mUMysYtmUovYómiTUsFUyomUMysYtmUaodsYomUlysUsFdmUmcγ,→⇒δ[+β∑β⇒δ(√,⇔→∑β⇒γβ+→+⇔→+θβ√√(⇒+
dYmoF sYFmiU SsiU sisósodvU sFdYycdyYmiíU "mU MysYtmU cvYdmodsTU sFU yomU MysYtmU aodsYomU lysU sFdmU
→√γ,→⇒δ[+→∑→⇔β⇔→β⇒γβ+→+⇔→+θβ√√(⇒+γ∑→⇒θ)β∑θ→⇔+δβ⇔UsisósodvUsFdYycdyYmiíU3vYUivFUsMscdvFUlysU
2β⇒β∑→⇒+ θγ→θ+ −,β∑•→θ+ (⇒γβ∑⇒→θω+ θβ+ ⇔βθ+ →θ[√(→+ √[⇒+ ⇔vFU sisósodvFU óscCoacvFU SsiU sisósodvU
sFdYycdyYmi0UcvocsudvFUlysUFsUmomiatmoUsoUsiUFa%yasodsUcmuadyivíU
U
2.10 CONDICIONES DE EQUILIBRIO. 
 
noUsiUcvods(dvUSsUimUdsvY'mUSsUimUnFdCdacmTUFsUSacsUlysUyoUFaFdsómUSsUMysYtmFUFsUsocysodYmUsoU
slyaiaeYavUcymoSvUFyUYsFyidmodsUsFUa%ymiUmUcsYv0UsFγ[+βθ<+
:: ====
∑∑ RRMMyFF U
U
Τ+](β⇒+δβθδβ+β⇔+,⇒γ[+δβ+)(θγ→+βθ√→⇔→∑<+

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  46  -U
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L+=⇒+β⇔+βθ→√([+β(θγβ⇒+↑+β√,→√([⇒βθ<+
U
∑∑∑ === :0:0:
ZYX
FFF U
∑∑∑ === :0:0:
ZYX
MMM U
U
L+=⇒+β⇔+⇔→⇒[+β(θγβ⇒+φ+β√,→√([⇒βθ<+
∑∑∑ === :0:0:
ZYX
FFF U
noUemFsUSsUivUmodsYavYTUimFUcvoSacavosFUSsUslyaiaeYavUumYmUyomUsFdYycdyYmUsoUsiUuimovUsFdCoU
YsuYsFsodmSmFUuvYUdYsFUscymcavosFUlysUovFUFsY aYCoUumYmUSsdsYóaomYUimFUYsmccavosFUSsUmuvgvíU
U
8aoUsóemY%vTUmUsFdmFUscymcavosFUSsUimUsFdCdacmTUyFymiósodsUuysSsoUmCmSaYFsUvdYmFUscymcavosFTU
iimómSmFU^sFuscamisF_UvYa%aomSmFUuvYUimUuYsFsocamUSsU^mYdacyimcavosF_U sYUMa%U2í+7U
U
articulación
U
Figura 2.15 
3→+→∑γ(√,⇔→√(⇒+(⇒γ∑[δ,√β+,⇒→+β√,→√(⇒+βθβ√(→⇔ω+→+θ→]β∑<+
UUUUUUUUUUUUUUUUUUU
:=
∑M +→+⇔→+(•′,(β∑δ→+[+δβ∑β√ϕ→+δβ+⇔→+→∑γ(√,⇔→√(⇒+
2.11     GRADO DE ISOSTATICIDAD. 
=⇔+ ^2∑→δ[+ δβ+ ∞Τ∞P∆P{∆_+ δβ+ ,⇒→+ βθγ∑,√γ,∑→+ θβ+ δβMaosU ósSamodsU imU Fa%yasodsU
β∑βθ(⇒<+
U
YU4U1UIUnUIsU
U
[⇒δβ<+
U R => Numero de reacciones (depende del numero y del tipo de apoyos) 
  E => Ecuaciones de la estática (en el plano 3 y en el espacio 6) 
  e => Ecuaciones especiales 
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  47  -U
U
.Y  Fj  óeXYdEjdnYeXY  Y7trYvXjf  vY  (ó  tjsEsj  sYnjvXdóYU ivFU dYsFU sFcsomYavFU lysU FsU uysSsoU
uYsFsodmYU soU siU moCiaFaFU SsU yomU sFdYycdyYmU umYmU SsdsYóaomYU imFU cvoSacavosFU SsU aFvFdmdacaSmSTU lysU mU
nóeYdó sY dYvrnYe vY Y7tjeY ó cjeXEerócE3e1 
U
Tabla 2.3   Grados de isostaticidad de una estructura 
 voSacavosFUSsU
EvjvXóXEcEsós1 
.EpYdYecEó YeXdY Fóv Eec35eEXóv u 
scymcavosFUSsUslyaiaeYavU
PauvUSsUsFdYycdyYmU
U
YU`U:U
nU5U)U4U%YmSvUSsUiaesYdmSUSsUimU
sFdYycdyYmU
G)3>8PUP) IU
vUsFdYycdyYmUaosFdmeisU
YU4U:U  n1>U
)8>8PUP) IU
vUsFdCdacmósodsU
SsdsYóaomSmU
YUaU:U
)U5UnU4U%YmSvUSsUaFvFdmdacaSmSUSsU
imUsFdYycdyYmU
G)3n1n8PUP) IU
vUsFdCdacmósodsU
aoSsdsYóaomSmU
 
Donde:    
 I  => numero de incógnitas 
E => numero de ecuaciones de la estática 
2.12  CARACTERIZACION DE LAS CARGAS. 
 vóvUgmU!me'móvFUósocavomSvUsoUsiUmoCiaFaFUSsUsFdYycdyYmFUimFUcmY%mFU  FsUuysSsoUmomiatmYU
cvóvUcmY%mFUuyodymisFUvUcvocsodYmSmFTUcmY%mFUm(amisFTUcmY%mFUovUm(amisFU*cvoUs(csodYacaSmS,TUcmY%mFU
SaFdYaeyaSmFUgUcmY%mFUovUyoaMvYósFíU
U
2.13   RESULTANTE DE CARGAS DISTRIBUIDAS LINEALMENTE. U
Sódó óF5rejv tdjt3vEXjv Yv cjexYeEYeXY vrvXEXrEd remUcmY%mUSaFdYaeyaSmUiaosmiósodsTUuvYUyomU
MysYtmUcvocsodYmSmU*uyodymi,UFs%#oUFsmUimUi'osmUSsUóccE3ef u sY Fó nEvnó nóeYdó vóiYd cróF Yv Fó 
tjvEcE3e sY sEc(ó cód5óz 
.YeXdj Fóv dYFócEjeYv nóXYnlXEcóv orY vY ótFEcóe tóYmUsiUcCicyivUSsUimUYsFyidmodsUSsUyomUcmY%mU
SaFdYaeyaSmUiaosmiósodsUivUs(uYsFmóvFUSsUimUFa%yasoXY nóeYdó1 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  48  -U
U
R
y
x
dx
dR
X (m)
L(m)
U
dxxdR ,*ω= U

=
l
dxxR
:
,*ω        [t] 
Además: 
     




=
l
l
dxx
dxxx
x
:
:
,*
,*ω
ω
   [m] 
Donde:  
 
⇒x  es la posición aproximada donde se encuentra la carga resultante R a lo largo de la 
viga. 
2.14  DETERMINACIÓN DE REACCIONES DE APOYO. 
noUsFdsUFyedadyivUFsUóvFdYmYCUsiUuYvcsSaóasodvUlysUFsUFa%ysUumYmUSsdsYóaomYUimFUYsmccavosFUsoU
⇔[θ+→[∫[θ+δβ+⇔→θ+βθγ∑,√γ,∑→θω+=Τ+∆DP=∞+=+DPΤ& )1D>8UnDUn8PnUIFE)P>UsFdmóvFU
veia%mSvFU mU Ys%aYovFU mU yomU
convención  de  signosTU lysU ovFU usYóadmU FviycavomYU imFU scymcavosFU
sFdCdacmFUSsUyomUómosYmUómFUFsocaiimUsFuscamiósodsUFaUFs%yaóvFUyoUuYvcsSaóasodvUmoCiaFaFUsFcmimYíU
 
=θγ→+βθ+⇔→+√[⇒)β⇒√(⇒+δβ+θ(2⇒[θ+δβ+⇔→+βθγ∴γ(√→ω+ β∑vUcymoSvUFsUSsFcvovcsUsiUFsodaSvUSsUimU
∑β→√√(⇒+βθ+√[⇒)β⇒(β⇒γβ+→θ,(∑+→∑→+β⇔⇔→+β⇔+θβ⇒γ(δ[UuvFada vTUgUFaUmiUYsmiatmYUsiUcCicyivUvedsosóvFUyoU
YsFyidmSvUuvFada vUFa%oaMacmYmUlysUsiUFsodaSvUmFyóaSvUFsYCUsiUcvodYmYavíU
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  49  -U
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2.15    EJERCICIOS RESUELTOS. 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  50  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  51  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  52  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  53  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  54  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  55  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  56  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  57  -U
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sFdmYCoUcvóusoFmSmFUuvYUimFUcmY%mFUYsmcda mFU*YsmccavosF,TUóvFdYmoSvUlysUs(aFdsUyoUslyaiaeYavUdmodvU
2β[γ∑(√[+√[[+(⇒γβ∑⇒[⋅+β⇒γ∑[+δβ+→∑√[θ+→√βγ→]⇔βθ+θβ+,βδβ+→√βγ→∑+′,β+β⇒+⇔→+)β∑(−(√→√(⇒+δβ+
β′,(⇔(]∑([+,⇒+β′,βC[+→∑2β⇒+δβ+β∑∑[∑<+HU:í:2TUumFmSvUsFdsUsYYvYUimUsFdYycdyYmUFsYCUcvoFaSsYmSmUcvóvU
sFdCdacmósodsUaosFdmeisíU
Ejercicio #5 
U 3mYmUimUFa%yasodsUsFdYycdyYmTUSsdsYóaomYUsiU mivYUSsUimFUYsmccavosFUSsUmuvgvíU
2
1.5 m
3 2
2 t
q=0.5 t/m
U
3YaósYmósodsUYsmiatmóvFUyoUmoCiaFaFUumYmU sYaMacmYUsiU%YmSvUSsUaFvFdmdacaSmSU
U
G = 3 – 3   = 0 ; Estructura ISOSTATICA 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  58  -U
U
U 3mYmUsMscdvFUSsUMmcaiaSmSUSsUcmicyivUuYsFsodmóvFUs⇒+β⇔+θ(2,(β⇒γβ+{3ω+⇒γβθβ+′,β+θβ+∑β→⇔(•→+β⇔+
moCiaFaFUFvivUcvoUimUYsFyidmodsUSsUimUcmY%mUSaFdYaeyaSmTUsFdmUsFUslya misodsUmUimUmodsYavYUsFdYycdyYmUusYvU
FvivUumYmUsMscdvFUSsUcmicyivUSsUYsmccavosFTUusYvUimFUsFdYycdyYmFUD>U8>DU)Y&I"n8íU
2 t
R=0.5x2=1.0 t
V
A

A
V
B
U
U nóuscsóvFUmomiatmoSvUimFUscymcavosFUMyoSmósodmisFUδβ+β′,(⇔(]∑([<+
U U U
:2:: =+⇒=⇔=
∑∑ AxHHF U
TS66í+:,7í+,*2*,*6,+,*+*: tVVM
BBA=⇒=+−⇒= ∑ U
U U U
TS66í::,2,*+*,*6,7í+,*2*: tVVM
AAB−=⇒=−−⇒=
∑ U
+ Dγβθβ+β⇔+θ(2⇒[+π+δβ+⇔→+∑β→√√(⇒+
ITUsFdvUovUlyasYsUSscaYUlysU!mgmóvFUYsmiatmSvUSsUómosYmU
β∑∑⇒β→+⇔[θ+√∴⇔√,⇔[θ+δβ+βθγ∴γ(√→ω+θ[⇔[+′,β+θβ+γ(β⇒βUlysUcmóeamYUsiUFsodaSvUlysU!me'móvFUmFyóaSvUumYmU
δ(√ϕ→+∑β→√√(⇒+β⇒+∑(β∑→+(⇒θγ→⇒√(→⋅+
2 t
1.0 t
0.33 t
2 t 
1.33 t
U
 >DP1>"UU
:66í:+66í+: =+−⇒=
∑V U
+ =θγβ+∑[√βδ((β⇒γ[+δβ+)β∑(−(√→√(⇒+√[⇒θ(θγβ+β⇒+∑β→iatmYUyomUFyómdvYamUSsUdvSvFUivFUsFMysYtvFU
s(aFdsodsFUsoUsiUsrsU^g_UvUdvSmFUimFUcvóuvosodsFUSsUcmY%mFUsoUFsodaSvU sYdacmiTUSac!mUFyómdvYamUSsesU
SmYU uvYU YsFyidmSvU csYvU *:,TU uvYU lysU mF'U sFdmYCU cvoMaYómSvU lysU ivFU sFMysYtvFU SsU imFU cmY%mFU mcda mFU
sFdmYCoUcvóusoFmSmFUuvYUimFUcmY%mFUYsmcda mFU*YsmccavosF,TUóvFdYmoSvUlysUs(aFdsUyoUslyaiaeYavUdmodvU
2β[γ∑(√[+√[[+(⇒γβ∑⇒[⋅+β⇒γ∑[+δβ+→∑√[θ+→√βγ→]⇔βθ+θβ+,βδβ+→√βγ→∑+′,β+β⇒+⇔→+)β∑(−(√→√(⇒+δβ+

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  59  -U
U
I2TODOC5OS TU 1I2TICS a”5%IU “I I55S50 HU:í:+TUumFmSvUsFdsUsYYvYUimUsFdYycdyYmUFsYCUcvoFaSsYmSmUcvóvU
sFdCdacmósodsUaosFdmeisíU
Ejercicio #6 
U 3mYmUimUFa%yasodsUsFdYycdyYmTUSsdsYóaomYUsiU mivYUSsUimFUYsmccavosFUSsUmuvgvíU
1.5 t
2t.m
q=1 t/m
A
B
C
4
3
223
1
U
O fidiOPZPlR'uOtPOZilYrYtitOtPOlirlXr'O(O'suPdMilY2aOdPirYyic'uOPrO1m4mhmOtPOriOOPuRdXlRXdiO
dvómoSvUsoUcysodmUFvivUimFUYsFyidmodsFUSsUimUcmY%mUSaFdYaeyaSmUusYvU sYaMacmoSvUFasóuYsUsiU%YmSvUSsU
aFvFdmdacaSmSíU
V
H
V
M
1.5 t
2t.m
R=0.5(5)(1)
A
B
C
1.5 t
2 t
2
2,67
A
A
B
B
U
G = 4 - 3 – 1   = 0 ; Estructura ISOSTATICA 
O AaOPuRPOliu'O'suPdMic'uOlXiRd'OYal2qaYRiuOód'MPaYPodsFUuvYUcmSmUyomUSsUimFUYsmccavosFU
socvodYmSmFTUumYmUSsdsYóaomYUFyU mivYUcvodmóvFUcvoURdPuOPlXilY'aPuOtPOriOPuRxRYliO(OXaiOPlXilY2aO
PuóPlYirOnXPOPuRiOtitiOó'dOriOidRYlXrilY2aOPaOPrOóXodvU íU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  60  -U
U
U nóuscsóvFUmomiatmoSvUimFUscymcavosFUMyoSmósodmisFUδβ+β′,(⇔(]∑([<+
U U ∑=:HU⇒U :2=+
AH U ⇒UUU 2−=
AH Ut 
U U ∑ =:
AM U⇒UU :2,7*7í+,2*7í+,9Jí2*2 =−++++
BBVM U
U U ∑ =:
BM UU⇒UU :2,6*7í+,9Jí+*27,+,*2* =++−++−−
BAMV U
U  vóvUgmU!me'móvFUósocavomSvTUsFdmFUdYsFUscymcavosFUSsUimUsFdCdacmUovUFvoUFyMacasodsFUumYmU
YsmiatmYU ivFU cCicyivFU oscsFmYavFTU usYvU FaU SsesóvFU yθ→∑+ ⇔→+ β√,→√(⇒+ βθβ√(→⇔+ ′,β+ βθγ→+ δ→δ→+ [∑+ ⇔→+
→∑γ(√,⇔→√(⇒+β⇒+β⇔+,⇒γ[+{ω+γ[→⇒δ[+βθγ→+β√,→√(⇒+βFuscamiUuvSsóvFUmomiatmYU!mcamUsiUimSvUlysUóCFU
dsUcvo so%mUumYmUMmcaiaSmSUSsUcCicyivU*atlyasYSmUvUSsYsc!m,íU
∑ =:M
C
DERECHA
UU
⇒UU :,*+2,+*7í+ =−++
BBVM U
+ {[⇒+βθγ→+β√,→√(⇒+[δβ[θ+∑βθ[⇔)β∑+β⇔+θ(θγβ→ω+⇔,β2[+γβ⇒β[θ+⇔[θ+θ(2,(β⇒γβθ+∑βθ,⇔γ→δ[θ<+
2t.m
R=0.5(5)(1)
A
B
C
1.5 t
2 t
2 t
0.59 t
3.59 t
0.11 t_m
U
 >DP1>"UU
:7<í67í+7í+7<í:: =+−−−⇒=
∑V U
Ejercicio #7 
3mYmUimUFa%yasodsUsFdYycdyYmTUSsdsYóaomYUsiU mivYUSsUimFUYsmccavosFUSsUmuvgvíU
33
3
V
H
A
A H
B
VB
A B
1 t.m
 0.6 t/m
C
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  61  -U
U
+ β→⇔(•→[θ+β⇔+⋅{⋅3⋅+δβ+⇔→++βθγ∑,√γ,∑→+γ[→⇒δ[+β⇒+cysodmUFvivUimFUYsFyidmodsFUSsUimUcmY%mU
SaFdYaeyaSmUgU sYaMacmoSvUFasóuYsUsiU%YmSvUSsUaFvFdmdacaSmSíU
U
V
H
A
A H
B
VB
A B
1 t.m
C
1.5
1
R=0.5(0.6)(3)
U
+ 3→+→∑γ(√,⇔→√(⇒+(⇒γ∑[δ,√β+→⇔+θ(θγβ→+,⇒→+β√,→√(⇒+SsUóvósodvTUlysUSsesUdvómYFsUmUimU
(•′,(β∑δ→+[+→+⇔→+δβ∑β√ϕ→+δβ+⇔→+→∑γ(√,⇔→√(⇒+β∑[+⇒[UmUmóevFUimSvFíUU
G = 4 - 3 – 1   = 0 ; Estructura ISOSTATICA 
 
IomiatmoSvUimFUscymcavosFUMyoSmósodmisFUSsUslyaiaeY([+γβ⇒β[θ<+
U U
∑=:H UU0UU :<í:=−+
BAHH U
U U ∑ =:
AM UU0UU :9,+*<í:,7í+*2í++ =−−+
BV U
U U U ⇒UUUU62í:=
BV UUtU
U U ∑ =:
BM UU0UU :9,+*<í:,7í;*2í++ =+−−
BV U
U U U ⇒UUUUU==í:=
AV UUtU
+ =√,→√(⇒+βθβ√(→⇔+++++++++∑ =:M
C
DERECHA
U
U U
⇒UUU :6,62í:*6,2*<í: =−−
BH UU⇒UU 2=í:=
BH UtUU0UUUU92í:=
AH Ut 
 
3mYmU sYaMacmYUYsmiatmóvFUsiUcvodYviUcvYYsFuvoSasodsíU
 >DP1>"UU
:62í:2í+==í:: =+−⇒=
∑V U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  62  -U
U
Ejercicio #8 
U 3mYmUimUFa%yasodsUsFdYycdyYmTUSsdsYóaomYUsiU mivYUδβ+⇔→+−,β∑•→+∑βθ,⇔γ→⇒γβ+∫+θ,+⇔ ⇒β→+δβ+→√√(⇒+
umYmUsiUFaFdsómU*m,UFmeasoSvUlysUM
*(,U4UumYCevimUSsU2SvU%YmSvíU
2 2 3
x
P1 P2
0.5 t 0.7 t
z3
1 2
6 t/m
f(x)
1 t.m
M1
U
*m,U
+ 3→++⇔ ⇒β→+δβ+→√√(⇒+βθγ→+∑β∑βθβ⇒γ→δ→+[∑+,⇒→+β√,→√(⇒ω+δβ+[δ[+′,β+βθ+∑β√(θ[+δβ√(δ(∑+,⇒+
FaFdsómUSsUcvvYSsomSmFTUsiUvYa%soUSsUSac!vUFaFdsómUuysSsUFadymYFsUsoUcymilyasYUuyodvUSsiUuimovUlysU
cvodasosUmUimFUMysYtmFTUusYvUsFUuYsMsYaeisUlysUsFdsUFsUFadymYmUsoUsiUiy%mYUómFUmSscymSvíU
x
R
dx
dR
x
3 m
6 t/m
f(x)
3
U
+ β→⇔(•→[θ+,⇒+√∴⇔√,⇔[+∑β)([<+
U U U U U S
RU4UM*(,Udx 
          y =
UM*(,U4Uk x
2
  
U U U U U 9U4U k LU6
2
U
⇒k =9V<UUU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  63  -U
U
U U U U UUUUU ⇒UUk =UU:í9JUU 
U U U U UUUUU ⇒UUM*(,U4U:í9JULUx
2
USt/mTU
+ ⇒γβ2∑→⇒δ[+γβ⇒β[θ+β⇔+)→⇔[∑+δβ+⇔→+∑βθ,⇔γ→⇒γβ<+
U U U U U

=
6
:
2
L9Jí:dxxR U
U U U U UUUUUU
⇒U tRR9<L9Jí: =⇒= UUU0UU vaocaSsocamU
+ ∆ϕ[∑→+ϕ→⇔⇔→[θ+⇔→+[θ(√(⇒+β→√γ→+δβ+⇔→+∑βθ,⇔γ→⇒γβUSsUimUcmY%míU
U U U 29í2
9
7Jí+6
9
9Jí:L;V6
,9Jí:*
;
6
:
2
====

R
dxxx
x UUm  
+ →∑→+(→2(⇒→∑⇒[θ+δβ+βα[∑+→⇒β∑→<+
xR(-P,0) Q(P,0)
P(x,y)
U
3QU4U31U
U I!vYmUuYvcsSsóvFUmU scdvYamiatmYUimFUMysYtmFíU
U U U
tP T:T7í:T:S
+ −=
r
U 0U T:T:T;S
+ −=r
r
U
U U
tPT:TJí:T:S
2
−=
r
U 0U T:T:T2S
2 −=r
r
U
U U U
mtMMT+T:T:S
+
=
r
U
U U U
tRT:T9T:S
+
−=
r
UU 0U T:T:T29í2S
6
=r
r
U
+ ∞→]β[θ+′,β<++
T:T2íJT:S
+2+ −⇔++= RPPF
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R
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U ∴U T+T:T:S
.
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:
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9
:
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.
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:
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+−

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R
r
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mtF
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−=+−++⇔
r
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  64  -U
U
U 8smUsiUuyodvUPUSsUcvvYSsomSmFUP 4USx ,0 ,0TUmω+,⇒+β⇔ββ⇒γ[+δβ+⇔→+⇔ ⇒β→+δβ+→√√(⇒+δβ+
RF
r
TU
sodvocsFU
RRPMFxr
rrr
=0UnFUSscaYUsiUóvósodvUSsUimUMysYtmUYsFyidmodsUF RUSsesUFsYUa%ymiUmUimUYsFyidmodsU
SsUóvósodvFíU
U U U∴U
kji
x
M
R
.
:
:
.
2íJ
:
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r
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⇒ T+9í<T:T:ST2íJT:T:S −=−x U
U U U U U ⇒ +9í<2íJ−=−x U
U U U U U ⇒ mx2Jí+= U
+ =θγ→+βθ+⇔→+β√,→√(⇒+δβ+,⇒→+∑β√γ→+→∑→⇔β⇔→+→⇔+βαβ+yíU
x
F=7.2 t
1.27
R
(b)
U
U 3vYU dmodvU siU FaFdsómU *m,U *cvóuisrv,U uysSsU FsYU FyFdadyaSvU uvYU siU FaFdsómU *e,U *Faóuis,TU FaoU
sóemY%vUmóevFUFaFdsómFUovUFvoUa%ymisFTUFvoUslya misodsFUumYmUcasYdvFUsMscdvFUSsUcCicyivíU
U
Ejercicio #9 
U "mUMa%yYmUóysFdYmUyomU ómoa simU>nTUsFmUuastmU sFdmUFyrsdmUmiUuimovU?AU ósSamodsU2U cmeisFU
*dsoFvYsF,TUsiUs(dYsóvU>UsFUyomUumFmSvYUsoUsiUsFumcavTUFsUuaSsUSsdsYóaomYUimFUYsmccavosFUSsUmuvgvUsoU
siUumFmSvYUgUsoUivFUdsoFvYsFíU
+ 3→θ+√[[∑δβ⇒→δ→θ+δβ+⇔[θ+,⇒γ[θ+β⇒+β⇔+βθ→√([+θ[⇒<+
U
6
:
2
A
UUSmTU
6
:
2−
B
SmTU
:
<
:
C
SmTU
6
<
:
D
SmTU
6
+6
:
E
SmTU
:
;
:
G
SmTU
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  65  -U
U
q2=0.2 t/m
q1=0.5 t/m
R=0.6t
R=0.8
0.8 t.m
T1
T2
O G C
D E
Z
X
Y
A
B
 
Vectorializar: 
U U6=í7T6T;T2S =⇒−⇔
→→
GAGA
U
U U U
T79í:TJ;í:T6Jí:S−⇔

uGA
r
U
U U
{
T79í:TJ;í:T6Jí:S
+++
aaaTuTTGA
a
−⇔⇒⋅⇔⇒

rrrr
U
U U 6=í7T6T;T2S =⇒−−⇔
→→
GBGB
U
U U U
T79í:TJ;í:T6Jí:S −−⇔

uGB
r
U
U U
{
T79í:TJ;í:T6Jí:S
222
bbbTuTTGB
b
−−⇔⇒⋅⇔⇒

rrrr
U
U U U
T:T:TS
++RR=
r
U U 0U T:T:T=í:S
+ −=M
r
U
U U
T:TT:S
22RR=
r
U U 0U T9í:T:T:S−=
∆R
r
U
U U U T T:T:S
66
RR=
r
U U 0U T=í:T:T:S−=
rec
R
r
U
U U U
T9í:T:T:S
−=Q
r
UU U
L
{ { {
TT:T:T:ST=í:9í:9í:79í:79í:TJ;í:J;í:T6Jí:6Jí:S:
77í2
6
9
2
:
+
=−−−+++−−+−⇒=

RbaRbaRbaF
t
R
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  66  -U
U
LLU ⇒=:
RM
r
U
:T:T:T=í:S
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:
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=−+
+−+−+−+−−+−
kjikjikjik
b
j
b
i
b
k
a
j
a
i
a
U
∴ :T:T:T=í:ST:T:T=í=ST:T:T+<=í9ST:T:T;í2ST;=í+T:T2;í2ST;=í+T:T2;í2S =−+−+−+−+++− bbaa U
U U TT:T:T:S,T*;=í+T:T+<=í+=,*2;í2S =−−+⇒ abba U
U U ba=⇒ U
  SolíU
2+:9í; TbtTa
rr
=⇔==⇒U
Ejercicio #10 
U 8sUuaSsUSsdsYóaomYUimFUYsmccavosFUSsUmuvgvUumYmUimUFa%yasodsUMa%yYmíU
A B
3 3 2,5
H
A
VA
H
B
VB
0.5 t/m
2 t/m
4
C
D
U
U /sYaMacmóvFUsiU%YmSvUSsUaFvFdmdacaSmSU
YU4U;UIU6UIU+UU4:UU
;  Estructura ISOSTATICAU
U 1smiatmóvFUsiUFa%yasodsUcCicyivUuYs avíU
U U U U
mLL 7;6
22
=⇒+= U
+ =⇔+∴⇒2,⇔[+δβ+(⇒√⇔(⇒→√(⇒+θβ∑∴<+
c6í76
7
;
7
;
==⇒= arcsensen
θθ U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  67  -U
U
U 1smiatmóvFUsiUcCicyivUSsUimUYsFyidmodsUSsUimUcmY%mUSaFdYaeyaSmUiaosmiósodsUmUivUimY%vUSsiUdYmóvU
{+⇔,β2[+∑β→⇔(•→[θ+β⇔+√∴⇔√,⇔[+δβ+⇔→θ+√[[⇒β⇒γβθ+)sYdacmisFUgU!vYatvodmisFíU
R
R
X
R
Y
U
U U tR
R
sen
Y
Y
27í2L,=:í:*
7í2
c6í76 ==⇒= U
U U tR
R
X
X
7í+7í2L,7<=í:*
7í2
c6í76cvF ==⇒= U
+ ∆⇔(√→⇒δ[+⇔→θ+β√,→√([⇒βθ+δβ+β′,(⇔(]∑([+γβ⇒β[θ<+
U U∑ =⇒=−⇒= tHHH
AA7í+:7í+:U
U U ∑ −=⇒−+−−⇒= tVVM
BBA 26í:7í=+2L7í+7í;L27í+L9:U
U U ∑ =⇒=++−+−⇒= tVVM
AAB26í;:+;L22L7í+7í=JL9:U
U 1smiatmóvFUsiUcvodYviUYsFuscda víU
 >DP1>"UU
:26í:2926í;: =−+−⇒=
∑V U
2.16   EJERCICIOS PROPUESTOS. 
Problema #1 
  βγβ∑(⇒→∑+⇔→θ+∑β→√√([⇒βθ+δβ+→[∫[+δβ+⇔→+θ(2,(β⇒γβ+Ma%yYmU
0.5 t/m
1 t/m
2 t
2,52,522222
A B E F C D
U
Respuesta:       
HA=0 t   ;       VA=0.75 t   
V
B=1.75 t   ;      VC=1.95 t      ;      VD=1.05 t 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  68  -U
U
Problema #2 
A B
1 t/m
 1 t/m
C
33
3
U
Respuesta:       
HA=1.5 t   ;    HB=1.5 t 
          V
A=3 t     ;    VB=0 t 
 
 
Problema #3 
  .YXYdnEeód Fóv dYóccEjeYv sY ótjuj1 
0.5 t/m
2 t
1.5 t/m
2.5 m
1.5 m
1 m
2 m
1 m
1.5
 m 2.5 m 1.5 m
2 m
1 t/m
A
B
C
U
Respuesta:       
HA=0.42 t     ;   HB=1.33 t 
          V
A=2.91 t     ;   VB=-4.246 t  
          V
C=1.957 t 
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  69  -U
U
 
Problema #4 
  .YXYdnEeód Fóv dYóccEjeYv sY ótjuj sY Fó vE5rEYeXY Ma%yYmU
2 m
4 m
1.5 m
1.5 m
2 t
2 m 2 m 2 m
A
C D E F
B
0.5 t/m
U
 
Respuesta:       
HA=2 t 
          V
A=1.75 t 
          V
B=1.083 t 
          M
B=7.298 t 
 
Problema #5 
  .YXYdnEeód Fóv dYóccEjeYv sY ótjuj sY Fó vE5rEYeXY Ma%yYmU
0.5 t/m
A D
C
B
0.3 t/m
4225
13
0.3 t.m
2
0.2 t
E
U
 
Respuesta:       
HC=0.2 t 
          M
C=0.7 t_m 
          V
B=1.31 t 
          V
A=0.14 t  
          V
C=0.25 t 
Problema #6 
  .YXYdnEeód Fóv dYóccEjeYv sY ótjuj sY Fó vE5rEYeXY Ma%yYmU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  70  -U
U
D E
0.3 t/m
4
1126
0.2 t/m
0.4 t/m
A C
B
0.5 t
U
Respuesta:       
HA=1.1 t 
          V
A=0.8 t 
          V
B=0.17 t 
          V
C=0.27 t 
 
Problema #7 
  .YXYdnEeód Fóv dYóccEjeYv sY ótjuj sY Fó vE5rEYeXY Ma%yYmU
A B
0.6 t/m
0.2 t/m

33
4
U
 
Respuesta:       
HA=2.30 t   ;    VA=3.06 t 
          H
B=0.7  t   ;    VC=0.13 t 
 
 
Problema #8 
  .YXYdnEeód Fóv dYóccEjeYv sY ótjuj sY Fó vE5rEYeXY Ma%yYmU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  71  -U
U
B
 1 t/m
3 3
6
A
U
Respuesta:       
HA=6 t 
          V
A=5.25 t 
          V
B=2.25 t 
 
 
Problema #9 
  .YXYdnEeód Fóv dYóccEjeYv sY ótjuj sY Fó vE5rEYeXY Ma%yYmU
B
1 t/m
2 t
2
3
2
4
A
U
 
Respuesta:       
HA=2 t      ;    VA=2.08 t 
          H
B=0 t     ;     VB=0.75 t 
          M
A=4.6 t_m 
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  72  -U
U
Problema #10 
  .YXYdnEeód Fóv dYóccEjeYv sY ótjuj sY Fó vE5rEYeXY Ma%yYmU
B
0.5 t/m
A
C D
1 t.m
33
4
1
U
Respuesta:       
HA=4 t      ;     VA=2.54 t 
          V
B=1.04 t 
           
 
Problema #11 
  .YXYdnEeód Fóv dYóccEjeYv sY ótjuj sY Fó vE5rEYeXY Ma%yYmU
0.2 t/m
Y
Z
1 t
x
EMPOTRAMIENTO
C B
A
C
D
O
2 t
1 t.m
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  73  -U
U
Respuesta:        Rx= 2.5 t     ;    Mx=8.25 t_m 
          R
y= -0.5 t    ;    My=15.5 t_m 
          R
z= 2 t      ;       Mz=-3.0  t_m 
 
 
 
Problema #12 
  βγβ∑(⇒→∑+⇔→θ+∑β→√√([⇒βθ+δβ+→[∫[+δβ+⇔→+θ(2,(β⇒γβ+−(2,∑→+δ→δ[θ+⇔[θ+θ(2,(β⇒γβθ+δ→γ[θ<+
7
:
6
7
:
6
2
J
:
+
7
: −
DCBA
U
Z
1 t
X
Y
T2
T1
C
D
A
B
U
Respuesta:       
HA=0.531    ;    VA=0.55 t t 
          H
B=0.031 t    ;    VB=2.55 t 
 
 
                   
2.17  EVALUACION DIAGNOSTICO DEL CAPITULO. 
 
 
→∑→+ ∑β→⇔(•→∑+ ,⇒→+ β)→⇔,→√(⇒+ δ(→2⇒[θγ(√[+ ∑β−β∑β⇒γβ+miU uYsFsodsU cmuadyivTU FsU uYvuvosU miU
sFdySamodsUYsFuvoSsYUimFUFa%yasodsFUuYs%yodmFíU
U β−(⇒(∑+β⇔+√[⇒√βγ[+δβ+ESTRUCTURAíU
U QysUsFUyoUmuvgvXU
U QysUdauvUSsUsFdYycdyYmFUs(aFdsoXU
U {,→⇔+βθ+⇔→+√⇔→θ(−(√→√(⇒+δβ+⇔→θ+βθγ∑,√γ,∑→θX+
U QysUdauvFUSsUmuvgvFUs(aFdsoUgUcymisFUFvoUivFU%YmSvFUSsUiaesYdmSUSsUcmSmUyovXU
U QysUsFUsiU%YmSvUSsUaFvFdmdacaSmSXU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  74  -U
U
U 3mYmU cvociyaYU sFdsU Sam%ovFdacvU FsU uaSsU SsdsYóaomYUimFU YsmccavosFU SsU muvgvU SsU imU Fa%yasodsU
Ma%yYmíU
2 t
0.5 t
5
3
A B
1,5 10 1,5
U
           
   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  75  -U
U
 
 
 
CAPÍTULO 3 
 
 
 
 
ESFUERZOS INTERNOS EN LAS 
ESTRUCTURAS 
 
3.1   OBJETIVO GENERAL. 
U
niUsFdySamodsUmuYsoSsYCUmUsimevYmYUivFUSam%YmómFUSs y+Ao+mof- )6 .34 6.6S6-234 S6mB-om34 
lysUFsUuYsFsodmoUsoUcymilyasYUuyodvUSsUyomUsFdYycdyA+ o4342B2om+ + 2A+yI4 )6 .+ )6)(mmof- )6 4(4 
1(-mo3-64 i )6 .+ A6.+mof- =(6 68o426 6-2A6 .+4 m+A%mFUs(dsYomFUcvoUimFUMysYtmFUaodsYomFUSsUimU
sFdYycdyYmíUU
U
3.2   OBJETIVOS ESPECIFICOS. 
 

IuYsoSsYCUcymisFUFvoUivFUsFMysYtvFUaodsYovFUSsUyomU642A(m2(A+ i 4+7AB 6- =(6 )oA6mmof- +m2M+- 
sFdmFU*ovYómiTUcvYdmodsUgUóvósodv,íU
U 0. 642()o+-26 +P.om+A+ (-+ m3-y6-mof- )6 4ov-34 +PAvuamSmUumYmUmuiacmYUmiUcCicyivUSsUivFU
sisósodvFUgmUósocavomSvFíU
U 0. 642()o+-26 +PA6-)6AB .34 )o42o-234 SI23)34 )6 +-B.o4o4 P+A+ .+ )626ASo-+mof- )6 .34 641(6At34 
aodsYovFUSsUivFUSaMsYsodsFUdauvFUSsUsFdYycdyYmFU* av+4L PfA2om34L +Am34L 642A(m2(A+4 So82+4Cn  
U 86vM- m+)+ SI23)3 +PA6-)o)3 A6+.ot+A+ )6 S+-6A+ m3S7o-+)+ .+ 6.+73A+mof- )6 .34 )o+vA+S+4 )6U
sFMysYtvFUaodsYovFíU
U 0. 642()o+-26 m3- .34 SI23)34 )6 +-B.o4o4 S6-mo3-+)vFTUSsóvFdYmYmUlysUimFUsFdYycdyYmFU
momiatmSmFUsFdCoUsoUslyaiaeYavUsFdCdacvíU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  76  -U
U
3.3   INTRODUCCION. 
) CNDCLPLSLDOICTEUICPECEQQ cDCMLCNDCY YOLSECMLCFNLJtmFUs(dsYovUFsUsocysodYmUsoUslyaiaeYavTU
QNEPRN LJCVIJQ cDCMLPCS YSIGCOEST rDCMLTLJBCMLCLDQIodYmYFsUsoUslyaiaeYavíUnFdsUsFUsiUuYaocauavUSsU
uyodvUSsUYsMsYsocamUumYmUlysUsiUiscdvYUsodasoSmUimUcmyFm5sMscdvUSsUyoUFaFdsómUSsUMysYtmFUs(dsYovUcvoU
yoU FaFdsómU SsU MysYtmFU aodsYov0U uYaocauavU lysU ovFU SsóysFdYmU imU MYvodsYmU sodYsU imU óscCoacmU SsU ivFU
cysYuvFUY'%aSvFUmFvcaCoSvimUmiUslyaiaeYavUs(dsYovUgUimUóscCoacmUSsUivFUcysYuvFUSsMvYómeisFTUcvoUsiU
slyaiaeYavUaodsYovíUU
noUsFdsUcmuadyivUFsUSsóysFdYmUcvóvUsocvodYmYUsiUsly P TJ IC DOLJDICECOJE1rYCMLCPECJLPEQ cDC
sodYsUimFUMysYtmFUs(dsYomFUgUimFUMysYtmFUaodsYomF0UJLYNPOEDMICMLCLYOECJLPEQ cDCPIYCLPLSLDOIYCSLQBD QIYU
RNLCYIDC5LDLJEMIYCVIJCPECEQQ cDCMLPCY YOLSECMLCFNLJtmFUs(dsYov0UgUlysTUuvYUFyFUsMscdvFUFsUcimFaMacmoU
IU0 -TI53” US5a”D ^D_ -SaS D” ETI53” OUPI5U” 2TI ”-O4ECVLJVLDM QNPEJCECPECYLQQ cDCOJEDY1LJYEPGCQIDC
NDC LFLQOIC MLC OLDY cDC IC MLC QISVJLY cD3C tNLJ.EC QIJOEDdsU ^/_TU cvóvU yomU MysYtmU aodsYomU lysU mcd#mU
VEJEPLPEC ECPECYLQQ cDCOJEDY1LJYEPGCQIDCNDCLFLQOIC MLCQIJOLCICMLFIJSEQ cDCMLCPECYLQQ cDCOJEDY1LJYEP3C
FvósodvUMis(avomodsU^F_TUcvóvUyoUóvósodvUaodsYovUlyLCEQO4ECVEJEPLPICECPECYLQQ cDGC5LDLJEDMICNDC
LFLQOICMLCFPLl cDGCVIJCPICOEDOIGCPEYCF TJEYCMLPCLPLSLDOICLYOJNQONJEPCLYOBDCYISLO MEYCECQISVJLY cDCIC
OLDY cD3CyISLDOICOIJY IDEDOLC^á_GCQISICNDCSISLDOIC DOLJDICRNLCEQO4ECVLJVLDM QNPEJCECPECYLQQ cDC
dYmoF sYFmiTUaSsodaMacCoSvFsUuvYUFyUsMscdvUSsU^dvYcsY_UmiUsrsUivo%adySaomiUFveYsUsiUcymiUsFdmUmcdymoSvíUU
iIDCPECMLF D Q cDGC MLDO F QEQ cDC2CQPEY F QEQ cDCMsUivFUsisósodvFUóscCoacvFUuvYUFyFUsMscdvFTU
FsU isU uYvuvYcavomU miU iscdvYU sisósodvFU SsU moCiaFaFU uEJEC LDQIDOJEJC PEC 1EJ EQ cDC MLC PIYC LPLSLDOIYC
SLQBD QIYC YITJLC LYOJNQONJEYC LDC FIJSEC MLC 1 5EYGC VcJOacvFU FaóuisFU gU mYcvFTU cvoFaSsYmoSvU cmY%mFU
YsumYdaSmFUsoUMvYómUYscdmo%yimYTUsoUMvYómUdYamo%yimJGCQEJ5EYCQIDQLDOJEMEYC2CSISLDOIYGCECOJE1rYCMLCPEC
MLMNQQ cDCMLCPEYCFNDQ IDLYCMLCPIYCLPLSLDOIYCSLQBD QvFUFsCmimoSvUivFUuyodvFUSsUSaFcvodaoyaSmSUSsU
PEYC QEJ5EYC LlOLJDEY=C 2C VIJC PEC JLPEQ cDGC LDOJLC PEC QEY%mU s(dsYomU cvoU imU MysYtmU cvYdmodsTU gU imU MysYtmU
cvYdmodsUcvoUsiUóvósodvUMis(avomodsíUU
3.4   DEFINICION Y ANÁLISIS DE LOS ELEMENTOS MECANICOS  INTERNOS. 
U
8aU aSsmiatmóvFU yoU sisósodvU sFdYycdyYmiU lysU FsU socysDOJEC LDC LRN P TJ IC TEUIC PEC EQQ cDC MLPC
FaFdsómUSsUMysYtmFUs(dsYovUYsuYsFsodmSvFUuvYUimFUcmY%mFU^3_0UcvóvUFsUóysFdYmUsoUimUMa%yYmU6í+*m,UgU
*e,TUdQysUFycsSsUFaUFveYsUsiUuimovUSsUcvYdsUaóm%aom5OS gI1”5”aSg ID -TI51SX0  
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  77  -U
U
 
Figura 3.1 (a)          Figura 3.1 (b) 
dnFdmY'mUSsUmcysYSvUsoUmcsudmYUlysUsiUsMscdvUlysUFsU%sosYmUmiUFsumYmYUsiUcysYuvUFveYsUsiUuimovU
SsUcvYdsUaóm%aomYavUsFUsiUYvóuaóasodvUSsiUslyaiaeYavUs(dsYovXTUFaUsFUmF'TUsodvocsFUovUFsUcyóuisUsiU
tdEecEtEj  sY  orY  ^vE  re  crYdtj  ióZj  Fó  óccE3e  sY  reU FaFdsómU SsU MysYtmFU s(dsYovU FsU socysodYmU soU
YorEFEidEjf cróForEYd tjdcE3e sYF crYdtj XóniE2e sYesYCUSsUsocvodYmYFsUsoUslyaiaeYav_0UuvYUivUdmodvTU
vYdl eYcYvódEj  YorEFEidód Fó tjdcE3e EaorEYdsó  u  sYdYc(ó  ó Xdóx2v sY re  vEvXYnó dYvrFXóeXY EeXYdej 
FjcóFEaósj Ye YF cYeXdjEsY sY Fó vYccE3e XdóevxYdvóF orY vYó YorExóFYeXY ó Fó óccE3e sYF vEvXYnó sY 
prYdaóv Y7XYdej sY cósó tjdcE3e z Sódó Fj óeXYdEjd jivYdxY Fó pE5rdó >zT1 
U
Figura 3.2 
Porción izquierda: ájidY YF cYeXdjEsY sY Fó vYccE3e XdóevxYdvóF vY FjcmiatmUyoUFaFdsómUYsFyidmodsU
aodsYovUaods%YmSvUuvYUimUMysYtmUYsFyidmodsU-1aUgUuvYUsiUóvósodvUYsFyidmodsUaodsYovUF1aTUslya misodsU
ó Fó óccE3e sYF vEvXYnó sY prYdaóv Y7XYdej orY ócXbó Ye Fó nEvnó tjdcE3e EaorEYdsóz  
Porción derecha: ke pjdnó óelFj5ó u vjidY YF cYeXdjEsY sY Fó vYccE3oUdYmoF sYFmiTUFsUivcmiatmU
yoU FaFdsómU YsFyidmodsU aodsYovU slya misodsU mU imU mcca3e  sY  Fóv  prYdaóv  Y7XYdeóv  orY  ócXbóe  vjidY  Fó 
tjdcE3e sYdYc(óR sEvXEe5rE2esjvY 2vXY vEvXYnó dYvrFdmodsUaodsYovTUuvYUdsosYUFsodaSvUcvodYmYavUmiUSsUimU
tjdcE3e EaorEYdsó tódó orY Y7EvXó YF YorEFEidEj EeXsYovUsodYsUmóemFUFsccavosFíUU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  78  -U
U
noU emFsU SsU ivU modsYavYU gU SmSvU lysU sFdmóvFU mevYSmoSvU siU cvocsudvU SsU YsFyidmodsTU sFU SsU
vrtjeYdvY orY 2vXY XEYeY vrv cjntjeYeXYv Ye Fó sEdYccE3e sY Fjv YZYv qf ”f u H dYvtYcXExónYeXYf 
dmodvUumYmUimUMysYtmUcvóvUumYmUsiUóvósodvUYsFyidmodYR Xjnóesj cjnj dYpYdYeXY Fó tjdcE3e EaorEYdsóf 
Fóv cjntjeYeXYv vY jivYdxóe Ye Fó pE5rdó >z>1  
U
Figura 3.3 
noUcvoFscysocamTUimFUcvóuvosodsFUSsiUYsFyidmodsUaodsYovU*dYsFUMysYtmFUcvóuvosodsFUaodsYomFUgU
dYsFUóvósodvFUcvóuvosodsFUaodsYovF,0UFsUisFUSsMaosUcvóvUsisósodvFUóscCoacvF0UlysUuvYUFyFUsMscdvFU
vY EsYeXEpEcóe1  
_rYdaó ejdnóF MC01 αóniE2e dYcjejcEsó cjnj _??UsFUimUMysYtmUcvóuvosodsUaodsYomUlysUmcd#mU
tYdtYesEcrFód ó Fó vYccE3e XdóevxYdvóFR vY EsYeXEpEcó tjd sjv YpYcXjv1 XYevE3e j cjntdYvE3ef 
 sYUMa%U6í;íUU
 
 
Figura 3.4
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  79  -U
U
_rYdaó cjdXóeXY MO01UnFdmUYsuYsFsodmSmUuvYU-?@U-?AU*sFdsUyidaóvUsoUsiUsFumcav,0UcvóuvosodsFU
EeXYdeóv orY ócXbóe tódóFYFónYeXY ó Fó vYccE3e XdóeF sYFmi0UFsUaSsodaMacmoUuvYUFyU sMscdvUSsU
cvYdsíU sYUMa%U6í7íU
 
Figura 3.5 
,jnYeXj XjdvEjeóeXY Mα01
UF??UóvósodvUcvóuvosodsUaodsYovUlysUmcd#mUusYusoSacyimYUmUimU
vYccE3e XdóevxYdvóFR vY FY EsYeXEpEcó tjd vr YpYcXj sY XjdvE3e óF YZY Fje5EXrsEeóF sYF YFYnYeXj 
sFdYycdyYmiíU
,jnYeXj  pFY7EjeóeXY  M,01U F?@U F?AU óvósodvFU cvóuvosodsFU aodsYovFU lysU mcd#moU
umYmisimósodsUmiUsrsUivo%adySaomiTUlysUFsUisFUmFvcaó re YpYcXj sY pFY7E3ez 
 
Figura 3.6 
 
3.5   CONVENCIÓN DE SIGNOS DE ESFUERZOS INTERNOS. 
g  cjeXEerócE3e  tdYvYeXónjv  Fó  cjexYecE3e  sY  vE5ejv umYmU ivFU sisósodvFU óscCoacvFU gU FyFU
YpYcXjvf  2vXY  vYdl  sY  ócrYdsj  óF  YpYcXj  orY  5YeYdó FveYsU siU sisósodvU sFdYycdyYmiíU 3mYmU siivTU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  80  -U
U
cvoFaSsYsóvFU yomU  a%mU FaóuisósodsU muvgmSmU cvoU cmY%mU cvocsodYmSmU miU csodYvU SsiU cimYvU cvóvU FsU
óysFdYmUsoUimUMa%yYmU6íJ*m,íUU
A C
30°
L/2L/2
P
B
 
Figura 3.7(a) 
 voU yoU Sam%YmómU SsU cysYuvU iaeYsTU ovFU usYóadaYCU aSsodaMacmYU siU FaFdsómU mcda vU gU siU FaFdsómU
Ysmcda vU sYUMa%U6íJU*e,U
R1=Psen30/2
R3=cos30
R2=Psen30/2
l/2 l/2
l/2 l/2
A CB
A C
30°
P
B
 
Figura 3.7 (b) 
PvómoSvU SsU YsMsYsocamU siU Sam%YmómU SsU cysYuvU iaeYsTUFveYsU siU dYmóvU IEU FsU ivcmiatmU yomU
vYccE3e  tYdtYesEcrFód  óF  YZY  Fje5EXrsEeóF  ó  reó  sEvXóecEó  q  sYF  YZY  gf  Fó  tjdcE3e  EaorEYdsó  sY  Fó 
sFdYycdyYmUFsUveFsY mUsoUimUfigura 3.8íUU
 
Figura 3.8 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  81  -U
U
ke ióvY sY Fj óeXYdEjdf Fó tjdcE3e EaorEYdsó ej vY socysodYmUsoUslyaiaeYav0UuvYUivUlysTUumYmU
slyaiaeYmYimUFsUYslyasYsUyoUFaFdsómUaodsYovUaods%Ymsj tjd sEpYdYeXYv YFYnYeXjv nYcleEcjvf YvXj Yv1 )ó 
óccE3e sY :
+U%sosYmUyomUMysYtmUaodsYomU sYdacmiUlysUmcd#mUumYmiYFónYeXY ó Fó vYccE3e XdóevxYdvóF Fó 
lysUFsUSsMaosUcvóvUMysYtmUcvYdmodsU/IBU0UmFaóaFóvTUimUMysYtmUs(dsYomU1
+TUgUimUaodsYomU/IBUuYvSycsoU
re 5Edj ó Fó tjdcE3e sY Fó YvXdrcXrdó 5YeYdóesj re umYUaodsYovUYsuYsFsodmSvUuvYUFIBTUlysUFsUSsMaosU
cjnj njnYeXj pFY7EjeóeXYR pEeóFnYeXYf Fó óccE3e sY imUMysYtmUs(dsYomU16U%sosYmUyomUMysYtmUaodsYomU
tYdtYesEcrFód  ó  Fó  vYccE3e  XdóevxYdvóF  CgBf  orY  vY SsMaosU cvóvU imU MysYtmU ovYómi0U ivU modsYavYU FsU
YsuYsFsodmUsoUimUfig >z]1  
 
Figura 3.9 
 
.Y Fj óeXYdEjd vY sYsrcY orY Fjv YFYnYeXjv nYcleEcjFU%sosYmSvFUuvYUsiUFaFdsómUs(dsYovUlysU
ócXbó  vjidY  Fó  tjdcE3e  sYdYc(ó  sY  Fó  YvXdrcXrdóf  vY  YorEFEidóe  cje  Fjv  5YeYdósjv  Ye  Fó  tjdcE3e 
EaorEYdsóR YvXj Yv1  
 
Figura 3.10 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  82  -U
U
8sYóFEaóesj  vjidY  Fó  vYccE3e  gB  re  YFYnYeXj  sY  Fje5adySU S(TU ivFU sisósodvFU óscCoacvFU
5YeYdósjv tjd YF vEvXYnó Y7XYdej sY cósó tjdcE3e vYUóysFdYmUsoUimUfig >z991   
 
Figura 3.11 
g  cjeXEerócE3e  óijdsódYnjv  cósó  rej  sY  Fjv  YFYnYeXjFU óscCoacvFU umYmU  aFymiatmYU FyFU
sMscdvFUlysUovFUusYóadmoUmFvcamYisUsiUFa%ovUcvYYsFujesEYeXY1  
3.5.1   Fuerza normal:
UIUimUMysYtmUovYómiUFsUisUmFvcamUsiUFa%ovUuvFada vUcymoSvUsiUsMscdvU
SsUimFUMysYtmFUs(dsYomFUlysUmcd#moUFveYsUsiimUFvoUSY XYevE3ez
 
 
Figura 3.12 
3.5.2   Fuerza cortante:
UIUimUMysYtmUcvYdmodsUFsUisUmFvcamUsiUFa%ovUuvFada vUcymoSvUimUcmY%mU
Y7XYdeó orY ócXbó vjidY Fó tjdcE3e EaorEYdsó sY Fó YvXdrcXrdó XEYeY reó sEdYccE3e xYdXEcóF cje 
FsodaSvUmFcsoSsodsíU
 
Figura 3.13 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  83  -U
U
3.5.3 Momento flexionante: UUIiUóvósodvUMis(avomodsUFsUisUmFa%omUsiUFa%ovUuvFada vU
cymoSvUsiUsMscdvUFveYsUimUMaeYmUFyusYavYUsFUSsUcvóuA6-4of-n 
 
Figura 3.14 
noUYsFyósoUdsosóvFUlysUla convención de signos en sentido positivo 46ABa 
M M
N
Q
Q
N
(+)
IZQ DER
U
Figura 3.15 
 
 
3.6   ANÁLISIS DE LAS ESTRUCTURAS. 
niUmoCiaFaFUSsUimFUsFdYycdyYmFTUuysSsUsoU%sosYmiUFy75)oyo)oA46 6-a 
U Análisis de vigas.  c+4 yov+4 43- 7+AA+4L 6- .+4 m(+.64 .+ )oA6mmof- )6iUsrsUcsodYvaSmiUsFU
umYmisimUmiU!vYatvodsU%sv%YCMacvíU
U Análisis de pórticos. c34 PfA2om34 43- 642A(m2(A+4 6- .+4 m(+.64L .+ )oA6mmof- )6 .34 6564 
csodYvaSmisFUSsUimFUemYYmFUovUsFUumYmisimUmiU!vYatvodsU%sv%YCMacvUFaovUlysUsiUsrsU(UcvaocaSsU
cvoUsiUsrsUivcmiUSsUimUemYYmíU
U Análisis de arcos. c34 +Am34 43- 642A(m2(A+4 6- .+4 m(+.64 .+ 6m(+mofoUSsiUsrsUcsodYvaSmiU
cvYYsFuvoSsUmUyomUcyY mU*ovUiaosmi,íU
U Análisis  de  estructuras  mixtas.  83-  .+4  =(6  642B-  m3SP(642+4  P3A  yov+4L  PfA2om34  iU
mYcvFíU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  84  -U
U
3.7   ANÁLISIS DE VIGAS. 
3.7.1 PROCEDIMIENTO DE ANÁLISIS 
&omU stUsodsoSaSvUlysUivFUsisósodvFUóscCoacvFUFvoU%6-6A+)34 P3A .+ +mmof- )6 (- 4o426S+ 
SsUMysYtmFUs(dsYovUlysUmcd#mUsoUyomUsFdYycdyYmTUsoUI426 +P+A2+)3 P.+-26+A6S34 6. PA3m6)oSo6-23 )6 
+-B.o4o4  P+A+  2A+t+A  .34  )o+vA+S+4  )6  y+Ao+mof-  m3AYsFuvoSasodsTU cvodsóuimoSvU umYmU siivU SvFU
PA3m6)oSo6-2340 .+ )6)(mmof- )6 .+4 1(-mo3-64 )6 .34 6.6S6-234 S6mB-om34 *SI23)3 )6 .+4 46mmo3-64 
3 +-B.o4o4 1(-mo3-+.C i .+ A6.+mof- )6 .+ m+Av+ 682sYomUcvoUimUMysYtmUcvYdmodsUgUimUMysYtmUcvYdmodsUcvoU
6. S3S6-23 1.68o3-+-26 *SI23)3 )6 4(S+ )6 BA6+4 3 +oCiaFaFUYsimcavomi,íU3mYmUsiivTUgUdvómoSvUSsU
7+46 .+ +P.om+mof- )6 (-+ m+Av+ m3-m6-2A+)+L )6 (-+UcmY%mUyoaMvYósósodsUSaFdYaeyaSmUgUSsUyomUcmY%mU
SaFdYaeyaSmUSsUMvYómUdYamo%yimYUFveYsUyomUsFdYycdyY+ *yov+ 3 7+AA+CL o)6-2o1om+A6S34 .+ y+Ao+mof- )6 .mU
MysYtmUcvYdmodsTUimUMysYtmUovYómiUgUsiUóvósodvUMis(avomodsUs(uYsFCoSvimUsoUFyUYsFuscda vUSam%YmómíUU
3.7.1.1    MÉTODO  DE  LAS  SECCIONES. 
U U PasosU cvóvU versda vU socvodYmYU imU
óm%oadySUSsUivFUsisósodvFUóscCoacvFUlysUFsUuYsFsodm- 6- (-+ 642A(m2(A+ o4342B2om+ + 2A+yI4 
)6 .+ )6)(mmof- )6 4(4 1(-mo3-64 A64P6m2oy+4 6- 6. cvods(dvUSsUyoUumYCósdYvUSsMaoaSv0UsoU
m3-46m(6-mo+L 6. +-B.o4o4 P+A+ )626ASo-+A I42+4 1(-mo3-64 642B .oSo2+)3 P3A .+ y+Ao+mof- )6 .+4 
cmY%mFUs(dsYomFUlysUmcd#moUsoUimUsFdYycdyYmíU3mYmUS6S342A+A .3 +-26Ao3A PA3P3-6S34a  
PRIMERO.-UIUumYdaYUSsUimUsFdYycdyYmUuimodsmSmTUFsUcvoFdYygsUyoUSam%YmómUSsUcysYuvU
.o7A6 P+A+ o)6-2o1om+Aa  
U El  sistema  de  fuerzas.- d+)3  =(6  46  +-+.ot+-  642A(m2(A+4  P.+-+4L  6.  4o426S+U SsU
MysYtmFU soU FyU cvoryodvU uvSYCU FsYU yoU FaFdsómU SsU MysYtmFU umYmisivU vU yoU FaFdsómU SsU
MysYtmFU%sosYmisFUsoUsiUuimovíUU
U El número de ecuaciones de equilibrio estático.-UnoUcvoFscysocamUSsUivUmodsYavYTUsiU
o#ósYvU SsU imFU scymcavosFU SsU slyaiaeYavU sFdCdacvU umYmU siU FaFdsómU SsU MysYtmFU soU FyU
m3-5(-23L 46 o)6-2o1om+AB- d>8 P+A+ 6. 4o426S+ )6 1ysYtmFUumYmisivUvUP1n8UumYmUsiU
FaFdsómUSsUMysYtmFU%sosYmisFUsoUsiUuimovíUU
U El  número  de  incógnitas.-U nFdCoU YsuYsFsodmSmFU uvYU imFU cvóuvosodsFU Ysmcda mFUvU
YsmccavosFUsoUcmSmUyovUSsUivFUmuvgvFUSsUimUsFdYycdyYmUgUcvoFaSsYmoSvUFyUFaFdsómUSsU
+P3i34 46 P3)AB o)6-2o1om+Aa rDe o-mfv-o2+ A6PA646-dmSmUuvYUimUcvóuvosodsUYsmcda mU
)6 (- +P3i3 Sfyo.0 d>8 o-mfv-o2+4 A6PA646-2+)+4 P3AUimFUcvóuvosodsFUYsmcda mFUsoU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  85  -U
U
(-  +P3i3  1o530  i  P108  o-mfv-o2+4  m(+-)3  46  2o6-6  (-U muvgvU aSsodaMacmSvU cvóvU
sóuvdYmóasodvíUU
U Las  condiciones  de  isostaticidad.-  Q)6-2o1om+)3  6.  -MS6A3  )6  .+4  o-mfv-o2+4  i  6. 
o#ósYvU SsU imFU scymcavosFU SsU slyaiaeYavU sFdCdacvU lysU cvodasosU siU FaFdsómU soU FyU
cvoryodvTU FsU dsoSYCoU sisósodvFU SsU moCiaFaFU umYmU mevYSmYU sFdYycdyYmFU cymoSvU imFU
m3-)omo3-64 )6 o4342+2omo)+) 46+- ov(+.640 6423 64aU)U4UníUU
U El  tipo  de  estructura.-U  voU siU YsFyidmSvU modsYavYTU sFdmYsóvFU soU cvoSacavosFU umYmU
mevYSmYUsiUmoCiaFaFUSsUyomUsFdYycdyYmUlysUFsUSsMaosUcvóvU)FvFdCdacmíUU
SEGUNDO.-UIuiacmoSvUimFUcvoSacavosFUSsUslyaiaeYavUFveYsUsiUSam%YmómUSsUcysYuvU
iaeYsTUFsUSsdsYóaomoUimFUYsmccavosFUumYmUsocvodYmYUsiUslyaiaeYavUs(dsYovíUU
TERCERO.-UIomiatmoSvUimUsFdYycdyYmUSsUatlyasYSmUmUSsYsc!mUvU acs sYFmUFs%#oUFsmU
siUcmFvUFsUaSsodaMacmoUivFUdYmóvFUlysUuYsFsodsoUcmóeavFUSsUMvYómUsoUimUcmY%mUs(dsYomTU
umYmUlysTUFveYsUcmSmUyovUSsUsiivFTUFsUcvoFdYygmUyoUSam%YmómUSsUcysYuvUiaeYsUaoSacmoSvUimU
+mmof-  )6  .+4  m+Av+4  6826A-+4  *=(6  +m2M+-  437A6  .+ P3Amof-  =(6  46  +-+.om6C  .+4  =(6  46 
!meYCoUSsUslyaiaeYmYUcvoUyoUYsFyidmodsUaodsYovTUaSs-2o1om+-)3 6- I426L .+4 m3SP3-6-264 =(6 
SsMaosoUmUivFUsisósodvFUóscCoacvFUlysUmcd#moUsoUsiUdYmóvUYsFuscda víUU
CUARTO.-U IuiacmoSvU imFU cvoSacavosFU SsiU slyaiaeYavU sFdCdacvUFsU SsSycsoU imFU
MyocavosFUSsUivFUsisósodvFUóscCoacvFUlysUFsUuYsFsodmoUsoUcmSmUdYmóvTUgUmiUFyFdadyaYUsoU
I42+4  .34  P+ABS62A34  )6  y+Ao+mof-  )6  .+  )o42+-mo+  ?U FsU vedasosoU imFU óm%oadySsFU
YsFuscda mFíUU
QUINTO.-U voUsiUYsFyidmSvUSsiUuyodvUmodsYavYUFsUuYvcsSsYCUmUdYmtmYUsiUSam%YmómUSsU
y+Ao+mof- P+A+ m+)+ 6.6S6-23 S6mB-om3 m3-4o)6A+-)3aUU
U Línea baseUSsUimUMysYtmUovYómiTUMysYtmUcvYdmodsUvUóvósodvUMis8o3-+-26a e P+A2oA )6 
yoUómYcvUSsUYsMsYsocamTUFveYsUsiUsrsU!vYatvodmiUFsUdYmtmUimUi'osmUemFsUFveYsUimUlysUFsU
o-)om+AB- .34 P+ABS62A34 )6 y+Ao+mof- )6 .+ )o42+-mamU^?_0UlysUFsUYsimcavomYCoUFveYsU
siUsrsU sYdacmiUsoUsiUlysUFsUivcmiatmYCoUimFUóm%oadySsFUSsUivFUsisósodvFUóscCoacvFU
YsFuscda vFíUU
U Trazo de la variación de los elementos mecánicos.-  voUivFUuyodvFUsocvodYmSvFUSsiU
A64(.2+)3 +-26Ao3AL 46 (-6 P(-23 + P(-23 3726-oI-)346 .+ y+Ao+mof- =(6 642+AB )61o-o)+ 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  86  -U
U
uvYUimFUMyocavosFUSsUivFUsisósodvFUóscCoacvFTUaSsodo1omB-)346 6- I42+4L .+4 4ov(o6-264 
m+A+m26Ab42om+4a  
3mYmU cymoSvU imU
carga  externa  es  nulaL  .+  1(-mof-  )6.  )o+vA+S+  )6  .+  1(6At+ 
cvYdmodsUsFUyomUi'osmU!vYatvodmiUgUumYmisimUmiUsrsU.3-vo2()o-+. + 2A+yI4 )6 (-+ 6m(+mof- )6 
imUMvYómU
“y =”UgUimUSsiUSam%YmómUSsiUóvósodvUMis(avomodsUFsUYsuYsFsodmUuvYUyomUi'osmU
o-m.o-+)+ =(6 376)6m6 + (-+ 6m(+mof- )6 .+ 13AS+
” y = mx + b”; íUU
3mYmU cymoSvU imU
carga  externa  es  uniformemente  distribuida  .+  1(-mof-  )6. 
Sam%YmómU SsU imU MysYtmU cvYdmodsU FsU YsuYsFsodmU uvYU yomU i'osmU aociaomSmU uvYU sFdmYU
m3-)omo3-+)+ + (-+ 6m(+mof- )6 .+ 13AS+ 
“y = mx + b”UgUimUSsiUSam%YmómUSsiUóvósodvU
Mis(avomodsUuvYUyomUi'osmUcyY mUSsUFs%yoSvU%YmSvUós)o+-26 (-+ 6m(+mof- )6 .+ 13AS+ 
“y 
= ax
2
 + bx + c”UU
3mYmUcymoSvUimU
carga externa es repartida de forma triangularL .+ 1(-mof- )6. 
Sam%YmómUSsUimUMysYtmUcvYdmodsUFsUYsuYsFsodmUuvYUyomUi'osmUcyY mUSsUFs%yoSvU%YmSvUuvYU
m3-26-6A (-+ 6m(+mof- )6 .+ 13AS+ 
“y = ax
2
 + bx + c”UgUimUSsiUSam%YmómUSsiUóvósodvU
Mis(avomodsUuvYUyomUi'osmUcyY mUSsUdsYcsYU%YmSvUcvo (-+ 6m(+mof- 
“y = ax
3
 + bx
2
 + cx + 
d”
íUU
U Valores críticos.- 0- m+)+ )o+vA+S+ )6 y+Ao+mof- )6 .34 6.6S6-234 S6mCoacvFUcvóvU
YsFyidmSvU SsiU uyodvU modsYavYTU FsU !meYCU SsU aSsodaMacmYU siU
valor  máximoU *uvFada vU gU
os%mda v,TU
mínimoUgUcero 23)34L A616Ao)34 + .+ .b-6+ 7+46 A64P6m2oy+0 6- I4dsUFyuysFdvUFsU
2o6-6a l(+-)3 .+ 1(6At+ m3A2+-26 P+46 P3A m6A3L 46 mFvcamUsoUsiUSam%YmómUSsiUóvósodvU
Mis(avomodsUyoU mivYUóC(aóvUlysUuysSsUFsYUuvFada vUvUos%mda v0UgUcymoSvUsiUóvósodvU
Mis(avomodsUumFsUuvYUcsYvUsiUuyodvUFsUSsMaosUcvóvUu(-23 )6 o-1.68of-n  
3.7.1.2 ANALISIS  RELACIONAL.
U U U nFU yoU uYvcsSaóasodvU SsU moCiaFaFU umYmU
)626ASo-+A  .+  y+Ao+mof-  )6  .34  6.6S6-234  S6mB-om34 YsimcavomoSvU imU cmY%mU s(dsYomU cvoU imU
MysYtmUcvYdmods0UgUimUMysYtmUcvYdmodsUcvoUsiUóvósodvUMis(avomodsTUsodYsUSvFUuyodvFUSsMaoaSvFU
soUyomUsFdYycdyYmíUU
3mYmU SsóvFdYmYU ivU modsYavYTU dvómYsóvFU SsU YsMsYsocamU imU sFdYycdyYmU aSsmiatmSmU lysU mU
m3-2o-(+mof- 46 S(642A+a  
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  87  -U
U
W t/m
R1
W t/m R2
12
P ton
dx
X
 
Figura 3.16
U
3mYdasoSvUSsiUFyuysFdvUlysUimUsFdYycdyYmUFsUsocysodYmUsoUslyaiaeYavTUsFdmUFsUSsMaosUcvóvUyomU
 a%mUFaóuisósodsUmuvgmSmUcvoUcmY%mUYsumYdaSmU*SsUMvYómUdYamo%yimYUgUyoaMvYós,UgUcmY%mUcvocsodYmSmU
imFUlysUsoUFyUcvoryodvTUYsuYsFsodmoUmiUFaFdsómUYsmcda v0UgUsiUFaFdsómUYsmcda vUsFdmUYsuYsFsodmSvUuvYU
imFUYsmccavosFU1
+UgU12UíU
)oacamYsóvFU siU moCiaFaFU mU umYdaYU SsU yoU sisósodvU SaMsYsocamiU SsU imU cmY%mU yoaMvYósósodsU
SaFdYaeyaSmUivcmiatmSvUmUyomUSaFdmocamU^?_UgUiaóadmSvUuvYUSvFUFsccavosFU*+UgU2U,UusYusoSacyimYsFUmiU
srsUivo%adySaomiUgUFsumYmSmFUyomUSaFdmocamUS(íU"vFUsisósodvFUóscCoacvFUlysUFsUuYsFsodmoUsoUcmSmU
yomUSsUimFUFsccavosFUFsCmimSmFTUFsUóysFdYmoUsoUimUFE5rEYeXY pE5rdó1  
U
Figura 3.17U
niU FaFdsómU óvFdYmSvU sFdmU cvóuysFdvU uvYU yoU
sistema  externoTU YsuYsFsodmSvU uvYU imU MysYtmU
YsFyidmodsUslya misodsUmUimUcmY%mUyoaMvYósósodsUSaFdYaeyaSmU
FR = W dx gUuvYUyoUsistema internoU
YsuYsFsodmSvUuvYUivFUsisósodvFUóscCoacvFU
M gUV orY vY tdYvYeXóe Ye Fó vYccE3e 9f u tjd (V + dV)UgU
(M + dM) Ye Fó vYccE3e TR Ye cjevYcrYecEóf YF vEvXYnó Ye vrUcvoryodvUFsUSsMaosUcvóvUyoUFaFdsómUSsU
MysYtmFUumYmisivUsoUsiUuimovíUU
gtFEcóesj Fóv YcrócEjeYv sY YorEFEidEj Y7XYdej1 árnmUSsUMysYtmFU sYdacmisFíUU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  88  -U
U
:,* =+−+ dVVWdxV UUUUUU0UUUUUUU : =−−+ dVVWdxV U
:=−dVWdx UUUUUUUUUUUUUU∴UUUUUUUUUUUUdVWdx=UUUUUUUscí*+,U
β+⇔→+β√,→√(⇒+++[]γβ⇒β[θ+
dx
dV
W
=ω+[∑+⇔[+γ→⇒γ[+θβ+,βδβ+→−(∑→∑+′,β<+
“La pendiente de la fuerza cortante esta representada por la carga externa”. 
⇒γβ2∑→⇒δ[+⇔→+β√,→√(⇒++[δβ[θ+[]γβ⇒β∑<+
∫∫
=
2
+
2
+
x
x
V
V
WdxdVU
∞(+⇔→+∑(β∑+(⇒γβ2∑→⇔+∑β∑βθβ⇒γ→+⇔→+)→∑(→√(⇒+δβ+⇔→UMysYtmUcvYdmodsUsodYsUimFUFsccavosFU+U
gU 2U TU gU imU Fs%yoSmTU siU CYsmU emrvU imU MvYómU SsU imU cmY%mU s(dsYomU sodYsU imFU FsccavosFU +U gU 20U
β⇒γ[⇒√βθ<+
“La variación de la fuerza cortante entre las secciones 1 y 2 es igual al área bajo la forma de la 
carga externa entre ambas secciones”. 
{[⇒+]→θβ+β⇒+⇔[+→⇒γβ∑([∑+θβ+γ(β⇒β+′,β<++
+2VVV −=∆UU0UCYsmUSsUimUcmY%mUs(dsYomUsodYsU+52U
∆⇔(√→⇒δ[+→ϕ[∑→+⇔→+θβ2,⇒δ→+√[⇒δ(√(⇒+δβ⇔+β′,(⇔(]∑([+βθγ∴γ(√[ω+√[⇒+θ,→+δβ+[β⇒γ[θ<++
:,*
2
=+−++ dMM
dx
WdxVdxMUUUUUU0UUUUUUU :: =−−++ dMMVdxM U
∴UUUUUUdMVdx=UUUUUUUscí*2,U
β+⇔→+β√,→√(⇒+++[]γβ⇒β[θ+
dx
dM
V=
ω+[∑+⇔[+γ→⇒γ[+θβ+,βδβ+→−(∑→∑+′,β<+
“La pendiente del momento flexionante esta representado por la fuerza cortante”. 
⇒γβ2∑→⇒δ[+⇔→+β√,→√(⇒+<++
∫∫
=
2
+
2
+
x
x
VdxdM
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  89  -U
U
3→+∑(β∑→+(⇒γβ2∑→⇔+∑β∑βθβ⇒γ→+⇔→+)→∑(→√(⇒+δβ⇔+[sodvUMis(avomodsUsodYsUimFUFsccavosFU+UgU
20UgUimUFs%yoSmUsiUCYsmUSsUimUMysYtmUcvYdmodsUsodYs+⇔→θ+(θ→θ+θβ√√([⇒βθ++∫++[∑+⇔[+γ→⇒γ[<++
 
“La variación del momento flexionante entre las secciones 1 y 2 es igual al área del diagrama de 
la fuerza cortante entre ambas secciones respectivamente”. 
=θγ[+βθ<++
+2MMM −=∆UU0UCYsmUSsiUSam%YmómUSsUMysYtmUcvYdmodsUsodYsUU+52U
{[⇒+]→θβ+δβ+⇔[+→⇒γβ∑([∑ω+⇔→+∑β⇔→√(⇒+β⇒γ∑β+⇔→+√→∑2→Us(dsYomUgUimUMysYtmUcvYdmods0UgUimU
MysYtmUcvYdmodsUcvoUsiUóvósodvUMis(avomodsTUumYmUSsγβ∑(⇒→∑+⇔→+)→∑(→√(⇒+δβ+⇔[θ+β⇔ββ⇒γ[θ+
β√∴⇒(√[θ+β⇒γ∑β+δ[θ+,⇒γ[θ+θβ+∑βθ,β<++
PRIMERO.-  "mUusoSasodsUSsUimUMysYtmUcvYdmodsTUsFdmUYsuYsFsodmSmUuvYUimUcmY%mUs(dsYomíUU
SEGUNDO.-++3→+)→∑(→√(⇒+δβ+⇔→+−,β∑•→+√[∑γ→⇒γβ+β⇒γ∑β+δ[θ+,⇒γvFTUsFUa%ymiUmiUCYsmUSsUimUcmY%mU
s(dsYomUsodYsUivFUóaFóvFUuyodvFUSsUYsMsYsocamíUU
TERCERO.- U "mU usoSasodsU SsiU óvósodvU Mis(avomodsTU sFdmU YsuYsFsodmSmU uvYU imU MysYtmU
cvYdmodsíUU
CUARTO.- + 3→+)→∑(→√(⇒+δβ⇔+[β⇒γ[+−⇔β([⇒→⇒γβ+β⇒γ∑β+δ[θ+,⇒dvFTUsFUa%ymiU miUCYsmUSsiU
δ(→2∑→→+δβ+)→∑(→√(⇒+δβ+⇔→+−,β∑•→+√[∑γ→⇒γβ+β⇒γ∑β+⇔vFUóaFóvFUuyodvFUSsUYsMsYsocamíUU
→∑→+γβ⇒β∑+,⇒→+√[⇒√β√(⇒+2∑→−(√→+δβ+⇔→θ+→⇔(√→√([⇒sFUSsU a%mFUsoUsFdYycdyYmFUcvóuisrmFU sYU
mos(vFUSsiUcmuadyivU6íU
U
EJERCICIOS RESUELTOS. 
→∑→+ [δβ∑+ γβ⇒β∑+ ,⇒→+ βα[∑+ β∑√β√(⇒+ δβ+ ⇔→+ (⇒γ∑[δ,√√(⇒+ →⇔+ →⇒∴⇔(θ(θ+ δβ+ ⇔→θ+ βθγ∑,√γ,∑→θ+
∑βθβ⇒γ→∑β[θ+→+√[⇒γ(⇒,→√(⇒+→+,⇒→+θβ∑(β+δβ+βαβ∑√(√([θ+∑βθ,β⇔γ[θ+[∑+⇔[θ+γ[δ[θ+∫→+β⇒√([⇒→δ[θ+
→⇒γβ∑([∑β⇒γβω+ →∑→+ →θ + ∑β→⇔(•→∑+ ⇔→+ )β∑(−(√→√(⇒+ δβU cmSmU dauvU SsU sFdYycdyYmU gU momiatmYU siU
√[[∑γ→(β⇒γ[++βθγ∑,√γ,∑→⇔+δβ+√→δ→+)(2→ω+γ→](⇒+→uYsoSsYUmU%YmMacmYUivFUSam%YmómFUSsUDTUQUgUFíU
Ejercicio #1 
3mYmU SsóvFdYmYU ivU modsYavYósodsU s(uysFdvTU FsU uYvuvoβ+ →+ √[⇒γ(⇒,→√(⇒+ →⇔(√→∑+ β⇔+ →⇒∴⇔(θ(θ+
−,⇒√([⇒→⇔+[+γ[δ[+δβ+θβ√√([⇒βθ+α,⇒γ→β⇒γβ+√[⇒+β⇔+γ[δ[+∑β⇔→√([⇒→⇔⋅+

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  90  -U
U
a) Método de las secciones o análisis funcional. 
l /2 l /2
BA C
U
3YaósYmósodsUYsmiatmóvFUyoUmoCiaFaFUumYmU sYaMacmYUsiU%YmSvUSsUaFvFdmdacaSmSU
G = 3 – 3   = 0 ; Estructura ISOSTATICA 
+ β→⇔(•→[θ+β⇔+√∴⇔√,⇔[+δβ+⇔→θ+∑β→√√([⇒βθ+δβ+→[∫[<+
TS
2
:,*,*7í:: t
WL
VVWLM
AAC
=⇒=+−⇒=∑
TS
2
:7í:,*: t
WL
VVWLM
CCA
=⇒=−⇒=∑ U
 >DP1>"UU
:2V2V: =−−⇒=
∑ WLWLWLV U
∆ϕ[∑→+θβ2,([θ+√[⇒+⇔→+[]γβ⇒√(⇒+δβ+⇔→θ+β√,→√([⇒βθ+δsUsFMysYtvFUaodsYovFUemFCoSvovFUsoUimU
√[⇒)β⇒√(⇒+δβ+θ(2⇒[θ+′,β+∫→+ϕβ[θ+[θγ∑→δ[⋅+
M M
N
Q
Q
N
(+)
IZQ DER
U
I!vYmTUsFUcvo soasodsUsFdmeiscsYUyoUFaFdsómUSsUYsMsYsocamTU!mcasoSvUcvaocaSaYUsiUsrsU
xUcvoUimU
δ(∑β√√(⇒+δβ⇔+βαβ+√β⇒γ∑[(δ→⇔+δβ+⇔→+)(2→+
w(x)
l /2 l /2
BA C
X
WL/2 WL/2U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  91  -U
U
8sUsMscd#mUyoUcvYdsUsoUimU a%mTU^8_TUóaFómUlysUFsUmomiatmYmUyomUivo%adySU?UsoUyoUYmo%vUSsU
ivo%adySUSsU a%mU^"_íU
Τ]θβ∑)β[θ+β⇔+∑(β∑[+√[∑γβω+θβ√√(⇒+^∞_+
w(x)
B
S
WL/2
x
Q
N
M
R
U
DOMINIO ⇔  Lx<<:  
 vYdmodsUQUU





=⇒=
−=⇒=
⇒−⇒
2
:
2
2
WL
Qx
WL
QLx
ParaWX
WL
U
8sU veFsY mU lysU cymoSvU ?4:TU imU MysYtmU cvYdmodsU dasosU yoU sMscdvTU uvFada vTU gU cymoSvU ?4"U
os%mda víU3vYUivUmodsYavYUFsUSsSycsUlysUimUMysYtmUcvYdmodsUSsUIUmU TUFveYsUmi%#oUuyodvU!meYCUSsUumFmYU
uvYUcsYv0UsoUcvoFscysocamTUimUSaFdmocamUSvoSsUvcyYYβ+⇔[+→⇒γβ∑([∑ω+⇔→+−,⇒√(⇒+δβ+⇔→+−,β∑•→+√[∑γ→⇒γβ+θβ+
(2,→⇔→+→+√β∑[ω+→∑→+δβγβ∑(⇒→∑+βθ[+βθ<+
VWX
WL
=−
2
+++β∑[+√,→⇒δ[+≤⌠ω+γβ⇒β[θ+′,β<+
22
L
XWX
WL
=⇒=
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trazo  del  diagrama  de  la  fuerza  cortante uYaósYvU FsU dYmtmU yoU ómYcvU SsU
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ivcmiatmUivFUuYaósYvFUumYCósdYvFUSsUimU mYameisU^?_UgUFveYsUsiUsrsU sYdacmiUFsUivcmiatmUimUóm%oadySUSsU
imUMysYtmUcvYdmodsUumYmUcmSmUumYCósdYvUSsUimU mYameisU^?_íU
&oasoSvUivFUuyodvFUSsFSsUIUcvoU?4:UgU/4:U!mFdmTUYsF,⇔γ→+⇔→+)→∑(→√(⇒+δβ+⇔→+−,β∑•→+√[∑γ→⇒γβ+
′,β+[]βδβ√β+→+⇔→+−,⇒√(⇒+′,β+θβ+[]γ,)[⋅+

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  92  -U
U
BA C
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trazo  del  diagrama  del  momento  flexionanteTU cvóvU gmU ósocavomóvFU
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umYCósdYvFUSsUimU mYameisU^?_UgUFveYsUsiUsrsU sYdacmiUimUóm%oadySUSsiUóvósodvUMis(avomodsUumYmUcmSmU
umYCósdYvUSsUimU mYameisU^?_íU
BA C
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y
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X=0 X=L/2 X=L
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2
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  93  -U
U
&omU stUYsmiatmSvUsiU%YmMacvUSsUivFUsFMysYtvFUaodsYovFUSsUimUsFdYycdyYmUuYvcsSsóvFUmUmovdmYU
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b) Método relacional. 
l /2 l /2
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w(x)
l/2 l/2
WL/2 WL/2
BA C
R
U
3vYUSmdvUFmesFUlysUimFUYsmccavosFUSsUmuvgvUsoU/
IUgU/  gSU0 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  94  -U
U
TS
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el 
diagrama de variación de la fuerza cortante
<+
{,→⇒δ[+?≤⌠ω+⇔→+−,β∑•→+√[∑γ→⇒γβ+β⇒+∆+βθ<+
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/EU4U/IUHU*CYsmUSsUimUcmY%mUs(dsYomUmcdymoSvUSsUIUm+E+βθγ[+βθ<+
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/ U4U/EUHU*CYsmUSsUimUcmY%mUs(dsYomUmcdymoSvUSsUEUm+{+βθγ[+βθ<+
/BcU4U:UHU*5[ULU"V2,U4UIU["V2UUUUmodsFUSsU U
U
FINALMENTE+⇔→+−,β∑•→+√[∑γ→⇒γβ+β⇒+{+βθ<+{+≤+B√+H+∑β→√√(⇒+βoU ,UU
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 voUivFUYsFyidmSvFUmodsYavYsFTUsiUSam%YmómUSsU mYam√(⇒+δβ+βθ−,β∑•[θ+δβ+⇔→+−,β∑•→+√[∑γ→⇒γβ+θβ+
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  95  -U
U
P'ciat'Ol'c'OdPZPdPalYiOPrOtYiqdiciOtPOMidYilY2aOtPUimUMysYtmUcvYdmodsUYsmiatmóvFUm!vYmU el 
diagrama de variación del momento flexionante

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2
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Ejercicio #2 
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a) Método de las secciones o análisis funcional. 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  96  -U
U
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G = 3 – 3   = 0 ; Estructura ISOSTATICA 
+ β→⇔(•→[θ+β⇔+√∴⇔√,⇔[+δβ+⇔→θ+∑β→√√([⇒βθ+δβ+→[∫[<+
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2/3L
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U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  97  -U
U
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2/3X
R
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Τ]θβ∑)β[θ+β⇔+∑(β∑+√[∑γβω+θβ√√(⇒+^∞_+
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UUUUUUUUUUUU/BIU4U["V9UIU
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  98  -U
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umYCósdYvUSsUimU mYameisU^?_íU
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U
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ivFU mivYsFUcY'dacvFUSsUimUsFdYycdyYmíU
Fuerza cortante máxima<+√,→⇒δ[++?≤3+√[⇒+→2⇒(γ,δ+[3Vφ⋅+
Fuerza cortante mínima<+√,→⇒δ[++?≤⌠+√[⇒+→2⇒(γ,δ+[3V↑++
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Sam%YmómUSsUMysYtmUcvYdmodsUumFmUuvYUcsYvíU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  99  -U
U
b) Solución por el método relacional. 
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 ymoSvU?4"TUcvoFaSsYmoSvUyoUuyodvUSaMsYsocamiUmodsF+δβ⇔+,⇒γ[+E+βθ<+
/ U4U/IUHU*CYsmUSsUimUcmY%mUs(dsYomUmcdymoSvUSsUIUm+E+βθγ[+βθ<+
/
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=⇒+]→θβ+→+⇔[+→⇒γβ∑([∑+θβ+[]θβ∑)→+γ→](⇒+′,β+√,→⇒δ[U?4:TUimUMysYtmUcvYdmodsUdasosUyoUsMscdvTU
uvFada vTUgUcymoSvU?4"Uos%mda víU3vYUivUmodsYavYUFsUSsSycsUlysUimUMysYtmUcvYdmodsUSsUIUmUETUFveYsU
mi%#oU uyodvU !meYCU SsU umFmYU uvYU csYv0U soU cvoFscysocamTU imU SaFdmocamU SvoSsU vcyYYsU ivU modsYavYTU imU
−,⇒√(⇒+δβ+⇔→+−,β∑•→+√[∑γ→⇒γβ+θβ+(2,→⇔→+→+√β∑[ω+→∑→+δβγβ∑(⇒→∑+βθ[+βθ<+
U
3→+ −,⇒√(⇒+ δβ+ ⇔→+ −,β∑•→+ √[∑γ→⇒γβ+ (2,→⇔→δ→+ →+ √β∑[+ βθ<++++++++++++
:2V+
9
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UUU4aUUUXU4U:í7JJUU"U
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2/3X
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A
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  100  -U
U
IomiatmoSvUSsUa%ymiUómosYmUumYmUsiUóvósodvUMis(avom⇒γβ<+





=∴=
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í:
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99
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M=0
0.0064WL
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CONCLUSIÓN:+3→+)→∑(→√(⇒+δβ⇔+δ(→2∑→→+γ→⇒γ[+δβ+⇔→+−,β∑•→+√[∑γ→odsUcvóvUSsiUóvósodvUMis(avomodsU
FvoUFaóaimYsFTUaoSsusoSasodsósodsUSsiUmoCiaFaFUlysUFsUmevYSs0UsFUSscaYTUSsiUmoCiaFaFUMyocavomiUvUsiUmoCiaFaFU
∑β⇔→√([⇒→⇔⋅+Τγ∑[+→θβ√γ[+([∑γ→⇒γβ+→+θβC→⇔→∑<+√,→⇒SvUimUcmY%mUs(dsYomUsFUyoaMvYósósodsUYsumYdaSmTUimU
−,⇒√(⇒+δβ+⇔→+−,β∑•→+√[∑γ→⇒γβ+βθ+,⇒→+⇔ ⇒β→+∑β√γ→+β+(⇒√⇔(⇒→δ→+∫+⇔→+−,⇒√(⇒+δβ⇔+[β⇒γ[+−⇔β([⇒→⇒γβ+βθ+,omU
i'osmUcyY mUSsUFs%yoSvU%YmSv0UmFaóaFóvTUcymoSvUFveYβ+⇔→+βθγ∑,√γ,∑→+βθγ→+→√γ,→⇒δ[+,⇒→+√→∑2→+,⇒γ,→⇔ω+θdmU
%sosYmU yoU cmóeavU eYyFcvU SsU imU MysYtmU cvYdmodsU gU Mao→⇔β⇒γβω+ β⇔+ [β⇒γ[+ β⇒+ ∆ω+ γ→](⇒+ 2β⇒β∑→+ ,⇒+
cmóeavUeYyFcvUSsiUóvósodvUMis(avomodsíU
→∑→+[δβ∑+∑β→⇔(•→∑+,⇒+→⇒∴⇔(θ(θ+,⇒+[√[+→θ+βγδ(√vUuimodsmóvFUmiUiscdvYTUyoUYscsdmYavUumYmUimU
∑βθ[⇔,√(⇒+δβ+)(2→θ+(θ[θγ∴γ(√→θω+(θ[+′,β+θβ∑∴+β⇔(√→δ[+→+√[⇒γ(⇒,→√(⇒⋅+
Ejercicio #3 
∞β+(δβ+→⇒→⇔(•→∑+⇔→+θ(2,(β⇒γβ+βθγ∑,√γ,∑→+[∑+β⇔+γvSvUSsUFsccavosFUvUmoCiaFaFUMyocavomiUryodmósodsU
√[⇒+β⇔+γ[δ[+∑β⇔→√([⇒→⇔⋅++

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  101  -U
U
A B
1 t/m
C
0.8 t.m
D
1.5 t
0.5 t1 t
1,5213
U
Paso 1)U1smiatmóvFUsiUcCicyivUSsUYsmccavosFUSsUmuvgvTUusYvUFvivUumYmUsMscdvFUSsUcmicyivUYsmiatmóvFU
siUcmóeavUSsUimUcmY%mUSaFdYaeyaSmUmUcmY%mUuyodymiíU
C
0.8 t.m
D
1.5 t
0.5 t1 t
VBVA
HA
R=3.0 t
U
U
1U4U6L+U4aUU14+U
tU
7í+:7í+: =⇒=−⇒=
∑ AAHHH
tVVM
BBA+=í2:,7íJ*7í:,*9=í:,;*+,7í+,*6*: =⇒=+−++⇒=

tVVM
AAB62í2:,7í+*7í:=í:,2*+,7í;*6,*9: =⇒=++−−⇒= ∑ U
 >DP1>"UU
:7í:+=í2+662í2: =−+−−⇒=
∑V U
Paso 2)+β→⇔(•→[θ+⇔→+[]γβ⇒√(⇒+δβ+⇔→θ+β√,→√([⇒βθ+δβ+βθ−,βYtvFUaodsYovFU
S S S S
C
V =2.32 t V =2.18 t
H =1.5 t
A
A
B
?f
?f
?
?
1 2 4 3
1 t/m 0.8 t.m
D
1.5 t
0.5 t1 t
U
=⇔+{3+′,β+θβ+,βθγ∑→+β⇒+β⇔+→θ[++∑β→⇔(•→[θ+β⇔+√→óeavUSsUimUcmY%mUSaFdYaeyaSmUmUcmY%mFU
uyodymisFTUusYvUFvivUumYmUsMscdvFUSsUMmcaiaSmSUSsUc∴⇔√,⇔[ω+→∑→+⇔→+[]γβ⇒√(⇒+δβ+βθ−,β∑•[θ+(⇒γβ∑⇒[θ+βθ+
oscsFmYavUdYmemrmYUcvoUimUcmY%mUSaFdYaeyaSmíU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  102  -U
U
noU sFdsU FsU !moU aodYvSycaSvU ;U FsccavosFU umYmU FyU moCiaFaFTU gU mU SaMsYsocamU SsU ivFU srsYcacavFU
modsYavYsFUsFdsTUFsUmomiatmYmUSsUmóevFUimSvFUSsUimU a%mUgUFsUYsmiatmYmUyoUcvodYviUsoUsiUoySvUaodsYósSavU
 íUumYmUivUcymiUaodYvSycaóvFUyoUsrsUSsUcvvYSsomSmFU(UIUgUlysUaYmUSsUatlyasYSmUmUSsYsc!mTUgUvdYvU(BUIU
gBTUlysUaYmUSsUSsYsc!mUmUatlyasYSmíU
SECCIÓN S
1 +++ΤFDΤ+

U:U`Ux `U6U
Normal   UDUU



−=⇒=
−=⇒=
⇒−⇒
tQx
tQx
Para 7í+:
7í+6
7í+ U
CortanteUQUU



−=⇒=
=⇒=
⇒⋅−⇒
tQx
tQx
Parax 9=í:6
62í2:
+62í2 U
Momento FUU



⋅=⇒=
⋅=⇒=
⇒⋅⋅−⋅⇒
mtQx
mtQx
Para
x
xx ;9í26
::
2
+62í2 U
1 t/m
V =2.32 t
H =1.5 t
A
A
?
1
Q
N
M
U
SECCIÓN S2 +++ΤFDΤ+

U6U`Ux `U;U
Normal   UDUU



−=⇒=
−=⇒=
⇒−⇒
tQx
tQx
Para 7í+;
7í+6
7í+ U
CortanteUQUU



−=⇒=
−=⇒=
⇒−⇒
tQx
tQx
Para 9=í:;
9=í:6
662í2 U
Momento FUU



⋅=⇒=
⋅=⇒=
⇒−−⋅⇒
mtMx
mtMx
Paraxx J=í+;
;9í26
,7í+*662í2 U
V =2.32 t
H =1.5 t
A
A
?
2
R=3.0 t
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  103  -U
U
SECCIÓN S3 +++ΤFDΤ+

U:U`Ux’ `U+í7U
Normal   UDUU



−=⇒=
−=⇒=
⇒−⇒
tNx
tNx
Para 7í+7í+f
7í+:f
7í+ UU
CortanteUUQUU



=⇒=
=⇒=
⇒⇒
tQx
tQx
Para 7í:7í+f
7í::f
7í: U
Momento FUU



⋅−=⇒=
⋅=⇒=
⇒−⇒
mtMx
mtMx
Parax J7í:7í+f
::f
f7í: U
D
1.5 t
0.5 t
S
? f
3
Q
N
M
U
SECCIÓN S4 +++ΤFDΤ+

U+í7U`Ux’ `U6í7U
U
0.8 t.m
D
1.5 t
0.5 t
S
V =2.18 t
B
?f
4
Q
N
M
U
Normal   UDUU



−=⇒=
−=⇒=
⇒−⇒
tNx
tNx
Para 7í+7í6f
7í+7í+f
7í+ UU
CortanteUUQUU



−=⇒=
−=⇒=
⇒−⇒
tQx
tQx
Para 9=í+7í6f
9=í+7í+f
+=í27í: U
Momento FUU



⋅=⇒=
⋅−=⇒=
⇒−+−−⇒
mtMx
mtMx
ParaXx J=:í+7í6f
77í+7í+f
,7í+f*+=í2=í:f7í: U
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  104  -U
U
Paso 3)U1smiatmóvFUsiUDIAGRAMA DE ESFUERZOS INTERNOS U
1 t/m 0.8 t.m
D
1.5 t
0.5 t1 t
C
V =2.32 t V =2.18 t
H =1.5 t
A
A
B
N
Q
M
1.5 t
1.5 t
1.5 t
1.5 t
1.5 t
2.69 t.m
2.46 t.m
1.78 t.m
1.55 t.m
0.75 t.m
(-)
(-)
(+)
(+)
(+)
(-)
U
 
Paso  4)
+ β∑(−(√→√(⇒+ δβ+ ⇔[θ+ βθ−,β∑•[θ+ βγ∑β[θ+ θβ20⇒+ →+ ⇔[θ+ γ[δ[θ+ ∫→+ β⇒√([⇒→δ[θ+ β⇒+ β⇔+
uYvcsSaóasodvUSsUcCicyivíU
DUU
tMin
tMax7í+
:−=
=
⇒ UUU QUU
tMin
tMax9=í+
62í2−=
=
⇒ U UUUUUUFUU
tMin
tMax77í+
9<í2−=
=
⇒ U
Ejercicio #4 
∞β+ (δβ+ →⇒→⇔(•→∑+ ⇔→+ θ(2,(β⇒γβ+ βθγ∑,√γ,∑→+ [∑+ β⇔+ γvSvU SsU FsccavosFU vU moCiaFaFU MyocavomiU
α,⇒γ→β⇒γβ+√[⇒+β⇔+γ[δ[+∑β⇔→√([⇒→⇔⋅++
2 t/m 1 t
A B
C D
E F
2 1 2 1 1 1
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  105  -U
U
Paso 1)++{U3{53Τ+=+=∆{{ΤD=∞+=+∆Τ@Τ⋅+
U

A
R=4 t

B V 
E V 
F
4 t
2 t 2 t
1 t
C D

A V 
B V 
E V 
F
2 t 2 t

A
PARTE IZQUIERDA
PARTE DERECHA
1 t
C D
U
U
∆P=+AQ5=∆++
C

A V 
B
2 t

A
U
U
U U U
tHH
A:: =⇒=
∑ U
tVVM
BBA6:,6,*2*,*2: =⇒=+⇒= ∑ U
U U U
tVVM
AAB+:,2,*+*,*2: −=⇒=+⇒=
∑ U
∆P=+=={G∆++
1 t
D

E V 
F
2 t
U
U
U U U
tVVM
FFE 7í::,*2,+*+,+*2: −=⇒=−+−⇒=
∑ U
U U U
tVVM
EEF7í6:,+*+,6*2,*2: =⇒=−−⇒=
∑ U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  106  -U
U
U
1 t
C D
1 t
R=4 t
3 t 3.5 t 0.5
U
 >DP1>"UU
:7í:+7í6;6+: =−−+−+−⇒=
∑V U
Paso 2)+ΤEP=D{ΤD+=+={5∆{ΤD=∞+=+=∞5=AΤ∞+DP=DΤ∞+
2 t/m 1 t
C D
1 t 3 t 3.5 t 0.5
1 2 3 6 5 4
x
x
x
x'
x'
x'
U
β+(2,→⇔+→⇒β∑→+θβ+(⇒γ∑[δ,√(∑∴+δ[θ+θ(θγβ→θ+δβ+√[[∑SsomSmFUumYmUlysUuysSmUFsYUmomiatmSvU
uvYUmóevFUimSvFTUyoUsrsUSsUcvvYSsomSmFU(UIUgUlysUaYmUSsUatlyasYSmUmUSsYsc!mTUgUvdYvU(BUIUgBTUlysUaYmU
SsUSsYsc!mUmUatlyasYSmíU
SECCIÓN S
1 +++ΤFDΤ+

U:U`Ux `U2U
U
Normal   UDUU



=⇒=
=⇒=
⇒⇒
tQx
tQx
Para :2
::
: 0U
N=0UUUumYmUdvSmFUimFUFsccavosFU
CortanteUUQUU



−=⇒=
−=⇒=
⇒−⇒
tQx
tQx
Para +2
+:
+ U
Momento FUU



⋅−=⇒=
⋅=⇒=
⇒−⇒
mtMx
mtMx
Parax 22
::
+ U
U
SECCIÓN S
2 +++ΤFDΤ+

U2U`Ux `U6U
CortanteUUQUU



=⇒=
=⇒=
⇒+−⇒
tQx
tQx
Para 26
22
6+ U
Momento FUU



⋅=⇒=
⋅−=⇒=
⇒−+−⇒
mtMx
mtMx
Paraxx :6
22
,2*6,*+
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  107  -U
U
niU mivYUSsUM=0UsoU(46TUFsUSmUuvYUlysUFsUsocysodYmUsoUimUmYdacyimc(⇒ω+√[[+∑β√[∑δ→∑β[θ+
,⇒→+→∑γ(√,⇔→√(⇒+[√→θ([⇒→+,⇒+β√,→√(⇒+βθβ√(→⇔+δβ+⇔aesYdmSUSsUóvósodvUmUyoUSsUivFUimSvFíU
SECCIÓN S
3 +++ΤFDΤ+

U6U`Ux `U7U
CortanteUUQUU



−=⇒=
=⇒=
⇒−−+−⇒
tQx
tQx
Parax 27
26
,6*26+ U
Momento FUU



⋅=⇒=
⋅=⇒=


−−−+−⇒
mtMx
mtMx
Para
x
xxx :7
:6
2
,6*
,6*2,2*6+ U
U
SECCIÓN S
4 +++ΤFDΤ+

U:U`Ux’ `U+U
CortanteUUQUU



=⇒=
=⇒=
⇒⇒
tQx
tQx
Para 7í:+f
7í::f
7í: U
Momento FUU



⋅−=⇒=
⋅=⇒=
⇒−⇒
mtMx
mtMx
Parax 7í:+f
::f
f7í: U
U
SECCIÓN S
5 +++ΤFDΤ+

U+U`Ux’ `U2U
CortanteUUQUU



=⇒=
=⇒=
⇒+⇒
tQx
tQx
Para 7í+2f
7í++f
+7í: U
Momento FUU



⋅−=⇒=
⋅−=⇒=
⇒−−−⇒
mtMx
mtMx
Paraxx 22f
7í:+f
,+f*+f7í: U
U
U
SECCIÓN S
6 +++ΤFDΤ+

U2U`Ux’ `U6U
CortanteUUQUU



−=⇒=
−=⇒=
⇒−+⇒
tQx
tQx
Para 26f
22f
7í6+7í: U
Momento FUU



⋅=⇒=
⋅−=⇒=
⇒−+−−−⇒
mtMx
mtMx
Paraxxx :6f
22f
,2f*7í6,+f*+f7í: U
U
U
Dys mósodsUsiU mivYUSsUF4:UcymoSvUiis%móvFUmUimUmYd(√,⇔→√(⇒⋅+
 
Paso 3)
UDIAGRAMA DE ESFUERZOS INTERNOS U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  108  -U
U
2 t/m 1 t
C D
1 t 3 t 3.5 t 0.5
N
Q
M
1 t
2 t
2 t
1.5 t
0.5 t
2 t.m 2 t.m
2 t.m
1 t.m
(+)
(+)
(+)
(-) (-)
(-) (-)
U
Paso 4)+β∑(−(√→√(⇒+δβ+⇔[θ+βθ−,β∑•[θ+βγ∑β[θ+θβ20⇒+→+⇔[θ+γ[δ[θ+∫→+β⇒√([⇒→δ[θ+β⇒+β⇔+
uYvcsSaóasodvUSsUcCicyivíU
DUU
tMin
tMax:
:=
=
⇒ UU QUU
tMin
tMax2
2−=
=
⇒ U UUUUUUFUU
tMin
tMax2
+−=
=
⇒ UU
Ejercicio #5 
∞β+ (δβ+ →⇒→⇔(•→∑+ ⇔→+ θ(2,(β⇒γβ+ βθγ∑,√γ,∑→+ [∑+ β⇔+ γvSvU SsU FsccavosFU vU moCiaFaFU MyocavomiU
α,⇒γ→β⇒γβ+√[⇒+β⇔+γ[δ[+∑β⇔→√([⇒→⇔⋅++
B
0.4 t.m
A
0.2 t/m
0.5 t/m
2 2 6
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  109  -U
U
Paso 1)++{U3{53Τ+=+=∆{{ΤD=∞+=+∆Τ@Τ⋅+
U
0.4 t.m
0.2 t/m
0.3 t/m R=0.9 t
R=1.2 t
1
2
M

A V 
B
H
B
B
4
3
C
U
U
3mYmUMmcaiadmYUsiUcCicyivUFsumYsóvFUimUcmY%mUdYmustvaSmiUsoU2UcmY%mFUSaFdYaeyaSmFTUyomU
dYamo%yimYUgUyomUYscdmo%yimYTUimFUlysUdsoSYCoUimFUFa%yasodsFUYsFyidmodsFTUcvóvUFsUóysFdYmUsoUimUMa%yYmU
→⇒γβ∑([∑<+
UtRR<í:,6í:*,9*
2
+
++
=⇒⋅⋅= U U tRR 2í+,2í:*,9*
+2=⇒⋅= U
U U
tHH
B:: =⇒=
∑ U
U U
tVVM
AA
IZQ
C
+í::,+:,*+í:*,*;:−=⇒=+⇒=
∑ U
U U
mtMRRMM
BBB ⋅=⇒=−−+−⇒=
∑ =íJ:,2V+,*9*,9,*6V2*;í:,+:*+í::
2+
U
U U
tVVM
BB
DER
C
2í2:9=íJ2í+,2V+*6V,<í:*:=⇒=−++⇒=
∑ U
U U U U
 >DP1>"UU
:2í22í+<í:+í:: =+−−−⇒=
∑V U
Paso 2)+ΤEP=D{ΤD+=+={5∆{ΤD=∞+=+=∞5=AΤ∞+DP=DΤ∞+
0.4 t.m
0.2 t/m
0.3 t/m
M

A V 
B
H
B
B
C
S
1 S
2
S
3
X
X
X'
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  110  -U
U
 
SECCIÓN S1 +++ΤFDΤ+

U:U`Ux `U2U
Normal   UDUU



=⇒=
=⇒=
⇒⇒
tQx
tQx
Para :2
::
: 0U
N=0UUUumYmUdvSmFUimFUFsccavosFU
CortanteUUQUU



−=⇒=
−=⇒=
⇒−⇒
tQx
tQx
Para +í:2
+í::
+í: U
Momento FUU



⋅−=⇒=
⋅=⇒=
⇒−⇒
mtMx
mtMx
Parax 2í:2
:í::
+í: U
SECCIÓN S
2 +++ΤFDΤ+

U2U`Ux `U;U
CortanteUUQUU



−=⇒=
−=⇒=
⇒−⇒
tQx
tQx
Para +í:;
+í:2
+í: U
Momento FUU



⋅=⇒=
⋅=⇒=
⇒+−⇒
mtMx
mtMx
Parax :;
2í:2
;í:,*+í:
 
SECCIÓN S
3 +++ΤFDΤ+

U:U`Ux’ `U9U
CortanteUUQUU



−=⇒=
−=⇒=
⇒⋅+⋅+−⇒
tQx
tQx
ParaXx +í:9f
2í2:f
f:27í:f2í:2í2
2
U
Momento F



⋅=⇒=
⋅−=⇒=
⇒−⋅⋅⋅−⋅−⇒
mtMx
mtMx
Paraxx
x
xx
:9f
=íJ:f
=íJ,f
6
+
*f:27í:
2
f
f2í:f2í2
2
U
Dys mósodsUsiU mivYUSsUF4:UcymoSvUiis%móvFUmUimUmYd(√,⇔→√(⇒⋅+
 
Paso 3)
+∆Y∆F∆+=+=∞5=AΤ∞+DP=DΤ∞+
+ Τ]θβ∑)β[θ+β⇔+δ(→2∑→→+δβ+)→∑(→√(⇒+δβ+βθ−,β∑•[θ+(⇒γβ∑⇒[θω+β⇒+⇔→+−(2,∑→+θ(2,(β⇒γβ<+

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  111  -U
U
0.4 t.m
0.2 t/m
0.3 t/m
M

A V 
B
H
B
B
C
N
Q
M
0.1 t
2.2 t
0.2 t.m
0.2 t.m
7.8 t.m
(-)
(-)
U
Paso  4)+ β∑(−(√→√(⇒+ δβ+ ⇔[θ+ βθ−,β∑•[θ+ βγ∑β[θ+ θβ20⇒+ →+ ⇔[θ+ γ[δ[θ+ ∫→+ β⇒√([⇒→δ[θ+ β⇒+ β⇔+
uYvcsSaóasodvUSsUcCicyivíU
DUU
tMin
tMax:
:=
=
⇒ UU QUU
tMin
tMax+í:
2í2−=
−=
⇒ UUUUUUUFUU
tMin
tMax=íJ
2íí:−=
=
⇒ U
3.8   ANÁLISIS DE PÓRTICOS 
Ejercicio #6 
PvómoSvU cvóvU YsMsYsocamU siU ómYcvU lysU FsU óysFdYmU soUimU Fa%yasodsU Ma%yYm0U SsdsYóaomYU imU
)→∑(→√(⇒+δβ+⇔[θ+β⇔ββ⇒γ[θ+β√∴⇒(√[θ+′,β+θβ+∑βθβ⇒γmoUsoUimUsFdYycdyYmTUlysUFvoU%sosYmSvFUuvYUimU
→√√(⇒+δβ+⇔→+√→∑2→+,⇒γ,→⇔+δβ+↑+γ[⇒⋅+∆√γ,→⇒δ[+β⇒+β⇔UuyodvU íU
4
2 2
4
A
B
C
D
E
6 t
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  112  -U
U
3.8.1 PROCEDIMIENTO DE ANÁLISIS. U
 "vFUcYadsYavFUSsUmoCiaFaFUumYmUSsdsYóaomYUsiUSam%YmS+ )6 y+Ao+mof- )6 .34 6.6S6-234 
óscCoacvFUlysUFsUuYsFsodmoUsoUyomUsFdYycdyYmUsoUsiUm3-26823 v63SI2Aom3 )6 (- S+Am3L 43- 
FaóaimYsFU mU ivFU lysU FsU muiacmYvoU soU ivFU mumYdmSvFU 9í+í+U gU 9í+í2U YsFuscda mósods0U sFU SscaYTU
ydaiatmoSvUsiUmoCiaFaFUMyocavomiUvUsiUmoCiaFaFUYsimcavomiTUsoUsFdYycdyYmFUsoUMvYómUSsU a%mTUusYvTU
sFUaóuvYdmodsUFsCmimYUSvFU mYamodsFUómFUlysUFsUydaiot+- P+A+ 6..3a 
U Primera
a  86  )61o-6  (-  S+Am3  )6  A616A6-mo+  v6-6A+.  6-  6.  m3ods(dvU SsU imU sFdYycdyYmTU
o-26vA+)3 P3A )34 6564 A6m2+-v(.+A64a (-3 u3Aot3-2+.a ? i 6. 32A3 y6A2om+.a @L 26-o6-)3 m3S3 
vYa%soUsiUovSvUIUdmiUcvóvUFsUóysFdYmUsoUimUMa%yYmíU
U Segunda:
UniUmoCiaFaFUSsUivFUsisósodvFUlysUaods%YmoUimUsFdYycdyYmU*dYmóvUIETUdYmóvUE TU
2A+S3 ldL i 2A+S3 d0CL 46 +73A)+- m3-4o)6A+-)3 (- 4sodaSvUSsUYscvYYaSvUuvYUimUumYdsUaodsYomU
)6  .+  642A(m2(A+  i  )6  ot=(o6A)+  +  )6A6mu+  )61o-oI-)visU mU cmSmU yovU SsU siivFU yoU ómYcvU SsU
YsMsYsocamUumYdacyimY0UuvYUsrsóuivTUumYmUsiUdYmóvUE TUFyUvYa%soUsFdCUivcmiatmSvUsoUsiUovSvUEU
SsUdmiUómosYmUlysUsoUsiUFsodaSvUSsUEUmU TUFsUaSsodaMacmUsiUsrsU!vYatvodmiUuvFada vU?0UgUsoUsiU
FsodaSvU sYdacmiUmUumYdaYUSsUEUsiUsrsU@íUU
3.8.2 DIAGRAMA DE CUERPO LIBRE U
 D34  P6ASo26  o)6-2o1om+Aa  c+4  m+Av+4  +m2oy+4  i  .+4 cmY%mFU Ysmcda mFíU niU FaFdsómU SsU
MysYtmFUlysUFsUmFvcamUcvoUimUsFdYycdyYmíUniUo#ósYvUSsUimFUscymcavosFUSsUslyaiaeYavUumYmUsiU
FaFdsómUSsUMysYtmFUSsdsYóaomSvíUniUo#ósYvUSsUimFUaomfv-o2+4 =(6 m3-2o6-6 6. 4o426S+n c+4 
cvoSacavosFUSsUaFvFdmdacaSmSUumYmUSsdsYóaomYUsiUdauvUSsUsFdYycdyYmUlysUFsUsFdCUmomiatmoSvíU
U Cargas activas: 
8sUaSsodaMacmU#oacmósodsUimUcmY%mUuyodymiUSsU9UdvoíUmcdymoSvUsoUsiUuyodvU
 íU
U Cargas  reactivas:
U nFdCoU YsuYsFsodmSmFU uvYU imFU YsmccavosFU soU cmSmU yovU SsU ivFU muvgvF0U
6423 64a 6- e 6. +P3i3 Sfyo. =(6 m3-2o6-6 (-+ m3SP3-6-26 A6+m2oy+ 6- .+ )oA6mmof- y6A2om+. 
1IíU noU nTU siU muvgvU MarvTU lysU cvodasosU SvFU cvóuvosod64  A6+m2oy+40  (-+L  6-  .+  )oA6mmof- 
y6A2om+. i .+ 32A+L 6- .+ )oA6mmof- u3Aot3-2+.L P6A3L )+)3 =(6 -3 68o426 m+Av+ 6826A-+ 6- I42+ 
)oA6mmof-L .+ m3SP3-6-26 64 ov(+. + m6A3n  
U 8o426S+ )6 1(6At+4 437A6 .+ 642A(m2(A+a 3+A+.6.3 6-UsiUuimovíUU
U Número  de  ecuaciones  que  contiene  el  sistema:  d340  4(S+  )6  1(6At+4  y6A2om+.64  i 
FyómUSsUóvósodvFíUU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  113  -U
U
U Número de incógnitas en el sistema:+[θ+⇔→+∑β→√√(⇒+)β∑γ(√→⇔+β⇒+∆ω<+∆ω+∫+⇔→+∑β→√√(⇒U
)β∑γ(√→⇔+β⇒+=<+=⋅++
U Condiciones de isostaticidad:
 2,→⇔βθ+βθγ[+βθ<+θ(+β⇔+⇒0β∑[+δβ+(⇒√2⇒(γ→θ++≤+ωU gUsiU
⇒0β∑[+δβ+β√,→√([⇒βθ+=+≤+ω+β⇒+√[⇒θβ√,β⇒√(→<++≤+=UuvYUivUdmodvUFsUdYmdmUSsUyomUsFdYycdyYmU
aFvFdCdacmíUU
PvómoSvUcvóvUYsMsYsocamUivUmodsYavYTUsiUSam%YmómUSs+√,β∑[+⇔(]∑β+δβ+⇔→+βθγ∑,√γ,∑→+βθ<++
B
C
D

A V 
E
x
6 t
U
Paso  1)UCálculo  de  reacciones:U IuiacmoSvU imFU cvoSacavosFU SsU slyaiaeYavU FveYsU siU Sam%YmómU SsU
√,β∑[+⇔(]∑β<++
tVVM
EEA6:,*;,9*2: =⇒=−⇒=
∑ U
mtVVM
AAE ⋅=⇒=−−⇒= ∑ 6:;,9*2: U
Paso 2) Análisis de los elementos estructurales.  
Análisis  del  tramo  AB:
U PvómoSvU cvóvU YsMsYsocamU siU moCiaFaFU MyocavomiTU imFU MyocavosFU SsU ivFU
sisósodvFU óscCoacvFU FsU vedasosoU muiacmoSvU FveYsU siUSam%YmómU SsU cysYuvU iaeYsU SsiU dYmóvTU imFU
cvoSacavosFUSsUslyaiaeYavUSsiUFaFdsómUSsUMysYtmFUlysUFsUisUmFvcamUsoUFyUcvoryodvíU3mYmUSsóvFdYmYUivU
modsYavYUdvósóvFUcvóvUYsMsYsocamUimUMa%yYmUlysUmUcv⇒γ(⇒,→√(⇒+θβ+,βθγ∑→<++

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  114  -U
U
TRAMO A-B +++ΤFDΤ+

U:U`Ux `U;U
U
 
Normal   
UDUU



−=⇒=
−=⇒=
⇒−⇒
tQx
tQx
Para 6;
6:
6 U
CortanteUUQUU



=⇒=
=⇒=
⇒⇒
tQx
tQx
Para :;
::
: U
MomentoUFUU



⋅=⇒=
⋅=⇒=
⇒⇒
mtMx
mtMx
Para :;
::
: U
U
U
Análisis del tramo BC:U3mYmUsiUsMscdvTUdvómYsóvFUcvóvUYsMsYsocamUimUsFdYy√γ,∑→+β′,(⇔(]∑→δ→<++
niUSam%YmómUSsUcysYuvUiaeYsUumYmUsiUdYmóvUE UFsUóysθγ∑→+→+√[⇒γ(⇒,→√(⇒<++
 voFaSsYmoSvUsiUómYcvUSsUYsMsYsocamUumYdacyimYUumYm+β⇔+γ∑→[+E{+∫+√[⇒+[∑(2β⇒+β⇒+β⇔+,⇒γ[+E<+
siUFaFdsómUSsUMysYtmFUlysUFsUaods%YmUsoUsiUSam%Ymóm+δβ+√,β∑[+⇔(]∑β+βθ<+
paralelo en la dirección del 
eje Y incluyendo pares
íU
PvómoSvU cvóvU YsMsYsocamU siU Sam%YmómU SsU cysYuvU iaeYsω+ ∫+ →⇔(√→⇒δ[+ θ[]∑β+ θγβ+ ⇔→θ+
cvoSacavosFUSsUslyaiaeYavUsFdCdacvUumYmUyoUFaFdsómUSsUMysYtmFUumYmisivTUFsUvedasosoUimFUMyocavosFUSsU
ivFUsisósodvFUóscCoacvFUlysUFsUuYsFsodmoUsoUsiUdYmó[+E{ω+′,β+→⇔+θ,θγ(γ,(∑+β⇒+θγ→θ+⇔[θ+→∑∴βγ∑[θ+δβ+
imUSaFdmocamU?TUYsFyidmUsoUcvoFscysocamUimUóm%oadySUSsUcmSmUyovUSsUivFUsisósodvFUóscCoacvFUlysUFsU
∑βθβ⇒γ→⇒+β⇒+β⇔+γ∑→[<++
TRAMO B-C 
+++ΤFDΤ+

U:U`Ux `U2U
 
Normal   
UDUU



=⇒=
=⇒=
⇒⇒
tQx
tQx
Para :2
::
: U
CortanteUUQUU



=⇒=
=⇒=
⇒⇒
tQx
tQx
Para 62
6:
6 U
MomentoUFUU



⋅=⇒=
⋅=⇒=
⇒⋅⇒
mtMx
mtMx
Parax 92
::
6 U
 
 
B
3 t
x
y
X
4
2
Q
N
M
B
C
3 t
x
X

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  115  -U
U
Análisis del tramo CD:+=⇔+δ(→2∑→→+δβ+√,β∑[+⇔(]∑β+→∑→+β⇔+γ∑→[+{+βθ<++
Función de los elementos mecánicos: 8aUsiUSam%YmómUSsUcysYuvUiaeYsUaods%YmUyoUFaFdsómUSsUMysYtmFU
umYmisivUsoUsiUuimovUaociygsoSvUumYsFTUimFUMyocavosFUSsUimUMysYtmUcvYdmodsUgUSsiUóvósodvUMis(avomodsU
FsUSsdsYóaomoUmuiacmoSvUimFUcvoSacavosFUSsUslyaiaeYavUFyFdadygsoSvUsoUimFUMyocavosFUYsFuscda mFTUivFU
→∑∴βγ∑[θ+δβ+⇔→+δ(θγ→⇒√(→+?<++
TRAMO C-D
++++ΤFDΤ+

U2U`U(U`U;U
Normal   UDUU



=⇒=
=⇒=
⇒⇒
tQx
tQx
Para :;
:2
: U
CortanteUUQUU



−=⇒=
−=⇒=
⇒−⇒
tQx
tQx
Para 6;
62
6 U
MomentoUFUU



⋅=⇒=
⋅=⇒=
⇒+⋅−⇒
mtMx
mtMx
Parax :;
92
+26 U
(x-2)
x
Q
N
M
B
C
3 t
X
6 t
U
Análisis  del  tramo  DE:U Dys mósodsU dvómYsóvFU cvóvU YsMsYsocamU siU Sam%YmómU SsU imU sFdYycdyYmU
β′,(⇔(]∑→δ→ω+ →∑→+ ′,β+ →+ →∑γ(∑+ δβ+ θγ→ω+ θβ+ δβ−(⇒→+ ,⇒+ δ(→2∑→→+ δβ+ √,β∑[+ ⇔(]∑β+ δβ⇔+ γ∑→[+ βθγ[+ βθ<+
Funciones  de  los  elementos  mecánicos:U  voFaSsYmoSvU lysU siU Sam%YmómU SsU cysYuvU iaeYsU lysU FsU
vedy vUsFdmUaods%YmSvUuvYUyoUFaFdsómUSsUMysYtmFUumYmisivUsoUsiUuimovUlysUaociygsUumYsFTUimFUMyocavosFU
SsUivFUsisósodvFUóscCoacvFTUFsUvedasosoUmiU muiacmYUimFU cvoSacavosFUSsUslyaiaeYavíU voUemFsUsoUivU
modsYavYUgUdvómoSvUcvóvUYsMsYsocamUivFUumYCósdYvFUSsUimUSaFdmocamU?TUimUóm%oadySUSsUivFUsisósodvFU
óscCoacvFUFsUSsdsYóaomoUmiUFyFdadyaYUYsFuscda mósodβ+β⇒+⇔→θ+−,⇒√([⇒βθ+⇔→+δ(θγ→⇒√(→+?<+

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  116  -U
U
TRAMO D-E +++ΤFDΤ+

U:U`Ux `U;U
Normal   UDUU



=⇒=
=⇒=
⇒⇒
tQx
tQx
Para :;
::
: U
CortanteUUQUU



=⇒=
=⇒=
⇒⇒
tQx
tQx
Para 6;
6:
6 U
MomentoUFUU



⋅=⇒=
⋅=⇒=
⇒⇒
mtMx
mtMx
Para :;
::
: U
Q
N
M
X
4
2 2
B
C
D
3 t
X
6 t
U
Paso 3)UDIAGRAMA DE ESFUERZOS INTERNOS:  3mYmUsiUsMscdvTUFsUdvómUcvóvUYsMsYsocamUivFU
 mivYsFUmovdmSvFUsoUivFUmoCiaFaFUSsUcmSmUdYmóvíU3mY→+γ→⇔+∑β→⇔(•→∑β[θ+βθγ[θ+δ(→2∑→→θ+β⇒+β⇔+∑γ(√[+
uvYUFsumYmSvíU
Diagrama de variación de la fuerza normal: 
(-) (-)
E
D3 t 3 t
4
B
C
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  117  -U
U
Diagrama de variación de la fuerza cortante: 
 
A E
D
3 t
3 t
B C
4
2 2
4
(+)
(-)
U
Diagrama de variación del momento flexionante: 
A E
D
6 t.m
B C
4
2
4
0 t.m 0 t.m
(+)
2
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  118  -U
U
Ejercicio #7 
PvómoSvU cvóvU YsMsYsocamU siU ómYcvU lysU FsU óysFdYmU soUimU Fa%yasodsU Ma%yYm0U SsdsYóaomYU imU
MidYilY2aOtPOr'uOPrPcPaR'uOcPlxaYl'uOnXPOuPOódPuPaR”U IU D” IgP5T-PT5”0 
2 t
1 t/m
3
3
4
A
B
C D
E
1
U
Procedimiento  de  análisis:U IuiacmYsóvFU siU moCiaFaFU YsimcavomiU umYmU SsdsYóaomYU ivFU sisósodvFU
óscCoacvFíUU
Primero:U 8sU cvoFdYygsU yoU Sam%YmómU SsU cysYuvU iaeYsU SsU imU sFdYycdyYmTU umYmU aSsodaMacmYU imFU cmY%mFU
mcda mFUgUimFUcmY%mFUYsmcda mFTUSsUdmiUMvYómUlysUovFUusYóadmUaSsodaMacmYUsiUFaFdsómUSsUMysYtmFUsoUFyU
cvoryodv0U siU o#ósYvU SsU scymcavosFU SsU slyaiaeYavU lysO uPO rPO iu'lYP9O PrO awcPd'O tPO Yal2qaYRiuO nXPO
cvodso%mU siU FaFdsómU soU %sosYmi0U imFU cvoSacavosFU SsUaFvFdmdacaSmSU umYmU  sYaMacmYU FaU imU sFdYycdyYmU FsU
1TI“I ”U”DO3”5 -SaS OgSgP4PO-”0 IgPS Ig0 
2 t
1 t/m
3
A
B
C D
E
VV
H
A
B
B
1
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  119  -U
U
Segundo:  CicyivU SsU YsmccavosF0U FsU vedasosoU muiacmoSvU FveYsUsiU Sam%YmómU SsU cysYuvU iaeYsU imFU
√[⇒δ(√([⇒βθ+δβ+β′,(⇔(]∑([<++
U U U
tHHH
EE762: =⇒++⇒=

U
tVVM
EEA +Jí;:,*6,;*2,6*7í+: =⇒=−+⇒= ∑
U
U U U
tVVM
AAE+Jí;,*6,;*2,6*7í+: =⇒−+⇒=

U
Tercero:U voUsiU mivYUSsUimFUYsmccavosFTUFsUSsMaosUimUsFdYycdyYmUslyaiaeYmSmUdmiUcvóvUFsUóysFdYmUsoUimU
θ(2,(β⇒γβ+−(2,∑→<++
2 t
1 t/m
3
3
4
A
B
C D
E
4.17
4.17
5
1
U
Cuarto:UIuiacmoSvUsiUmoCiaFaFUYsimcavomiTUgUdvómoSvUcvóvUYsMsYsocamUimUsFdYycdyYmUslyaiaeYmSmTUFsU
δβγβ∑(⇒→∑∴⇒+ ⇔[θ+ δ(→2∑→→θ+ δβ+ )→∑(→√(⇒+ δβ+ ⇔→+ −,β∑•mU ovYómiTU MysYtmU cvYdmodsU gU óvósodvU
−⇔β([⇒→⇒γβ<++
TRAMO A-B 
+++ΤFDΤ+

U:U`Ux `U6U
 
Normal   
UDUU



=⇒=
=⇒=
⇒⇒
tQx
tQx
Para +Jí;6
+Jí;:
+Jí; U
CortanteUUQUU



−=⇒=
=⇒=
⇒⋅−⇒
tQx
tQx
Parax 66
::
+ U
MomentoUFUU



⋅−=⇒=
⋅=⇒=
⇒⋅⇒
mtMx
mtMx
Parax
x 7í;6
::
2
U
U
U
1 t/m
3
A
B
4.17

x

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  120  -U
U
Análisis del tramo BC:U3mYmUsiUsMscdvTUdvómYsóvFUcvóvUYsMsYsocamUimUsFdYy√γ,∑→+β′,(⇔(]∑→δ→<++
niUSam%YmómUSsUcysYuvUiaeYsUumYmUsiUdYmóvUE UFsUóysθγ∑→+→+√[⇒γ(⇒,→√(⇒<++
TRAMO B-C 
+++ΤFDΤ+

U6U`Ux `U;U
U
 
Normal   
UDUU



=⇒=
=⇒=
⇒⇒
tQx
tQx
Para +Jí;;
+Jí;6
+Jí; U
CortanteUUQUU



−=⇒=
−=⇒=
⇒−⇒
tQx
tQx
Para 6;
66
6 U
MomentoUFUU



⋅−=⇒=
⋅−=⇒=
⇒−⋅⇒
mtMx
mtMx
Parax 7íJ;
7í;6
,7í+*6 U
 
 
 
Análisis del tramo CD:
+=⇔+δ(→2∑→→+δβ+√,β∑[+⇔(]∑β+→∑→+β⇔+γ∑→[+{+βθ<++
TRAMO C-D 
+++ΤFDΤ+

U:U`Ux `U6U
Normal   UDUU



−=⇒=
−=⇒=
⇒−⇒
tQx
tQx
Para 76
7:
7 U
CortanteUUQUU



−=⇒=
−=⇒=
⇒−⇒
tQx
tQx
Para +Jí;6
+Jí;:
+Jí; U
MomentoUFUU



⋅−=⇒=
⋅−=⇒=
⇒−⋅−⇒
mtMx
mtMx
Parax 2:6
7íJ:
,6*7í2+Jí; U
 
1 t/m
3
A
B
4.17
x
2 t
1
3
B
C
3
D
x
U
1 t/m
3
A
B
4.17
x  
x
2 t
1
3
B
C

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  121  -U
U
Análisis del tramo DE: 
TRAMO D-E +++ΤFDΤ+

U:U`Ux `U;U
Normal   UDUU



=⇒=
=⇒=
⇒⇒
tQx
tQx
Para :;
::
: U
CortanteUUQUU



=⇒=
=⇒=
⇒⇒
tQx
tQx
Para 6;
6:
6 U
MomentoUFUU



⋅=⇒=
⋅=⇒=
⇒⇒
mtMx
mtMx
Para :;
::
: U
x
2 t
1 t/m
3
3
A
B
C D
E
4.17
1
x
U
DIAGRAMA DE ESFUERZOS INTERNOS:  3mYmUsiUsMscdvTUFsUdvómUcvóvUYsMsYsocamUivFU mivYsFU
movdmSvFU soU ivFU moCiaFaFU SsU cmSmU dYmóvíU 3mYmU dmiU U Yβ→⇔(•→∑β[θ+ βθγ[θ+ δ(→2∑→→θ+ β⇒+ β⇔+ ∑γ(√[+ [∑+
FsumYmSvíU/sYUimFUFa%yasodsFUMa%yYmFíU
Diagrama de variación de la fuerza normal: 
A
B
C D
E
5 t
4.17 t 4.17 t
0 t
0 t
0 t
(+) (+)
(-)
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  122  -U
U
 
Diagrama de variación de la fuerza cortante: 
 
A
B
C D
E
4.17 t
3 t
5 t
0 t
0 t
0 t
(-)
(-)
(+)
U
Diagrama de variación del momento flexionante: 
A
B
C
D
E
20 t.m
4.5 t.m
20 t.m
0 t.m
0 t.m
0 t.m
DC
(-)
(-) (-)7.5 t.m
7.5 t.m
U
8s%#oU siU uYvcsSaóasodvU gmU ósocavomSvTU sFU cvo soasodsU sFcv%sYU yoU uyodvU U aodsYósSavU SsU
l'alPaRdilY2aOtPrOPuRXtY'mOAaOPuRPOóXaR'OuPOdPirYyidiOPrOl'aRd'rOdPuóPlRYM' O2uPiOriOMPdYZYlilY2aOtPO
dvSvFUivFUsisósodvFUsFdYycdyYmisFU*DvYómiTU vYdmodsTUFvósodv,íU
U
Ejercicio #8 
PvómoSvU cvóvU YsMsYsocamU siU ómYcvU lysU FsU óysFdYmU soUimU Fa%yasodsU Ma%yYm0U SsdsYóaomYU imU
MidYilY2aOtPOr'uOPrPcPaR'uOcPlxaYl'uOnXPOuPOódPuPaR”U IU D” IgP5T-PT5”0 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  123  -U
U
A
B
αααα
4
3
U
G = 3 – 3   = 0 ; Estructura ISOSTATICA 
Paso 1)
U CicyivUSsUYsmccavosFUSsUmuvgvíU
U RR
V
R
H
A
B
αααα
α
4 t
0
4 t
U
1U4U2L;U4aUU14U=U
tU
:: =⇒=
∑ BHH U
tVVM
BBA;:,*;,=,*2*: =⇒=−⇒= ∑ U
tVVM
AAB=í::,2*=,*;: =⇒=−−⇒= ∑ U
UUU >DP1>"UU
:2í+;í:=í:: =−+⇒=
∑V U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  124  -U
U
3mYmUYsmiatmYUsiUmoCiaFaFUSsUimUemYYmTUSaFdYaeyaYsóvFUimUcmY%mUSaFdYaeyaSmUsoUSvFUSaYsccavosFTUsoU
⇔→+δ(∑β√√(⇒+δβ+⇔→+]→∑∑→+∫+β∑β⇒δ(√,⇔→∑+→+β⇔⇔→ω+→YmUmF'USsdsYóaomYUivFUsFMysYtvFUaodsYovFíU
EmYYmU"U mLL 7;6
22
=⇒+=⇒ U
c=9í69
;
6
dmo
=⇒=αα U
tR
V
;í9cvF==⋅=α UUUU0UUU tsenR
H =í;= =⋅=α U
mtq
R
qqR
H
H
HHH
V<9í:
7
=í;
7
L7 =⇒==⇒= U
mtq
R
qqR
V
V
VVV
V2=í+
7
;í9
7
L7 =⇒==⇒= U
Paso 2)+Τ]γβ⇒√(⇒+δβ+⇔→θ+β√,→√([⇒βθ+δβ+βθ−,β∑•[θ+(⇒γβ∑⇒[θ⋅U
A
B
4 t
R
V
RH
0.96 t/m
1.28 t/m
36.86°
4 t
U
U
βθ√[[⇒β[θ+γ→](⇒+⇔→θ+∑β→√√([⇒βθ+δβ+→[∫[+β⇒+δ(∑β√√(⇒+δβ+⇔→+)(2→⋅++
UUUUUUUUUUUUUU
N = 4 * 0.6 = 2.4  t 
Q = 4 * 0.8 = 3.2  t 
U
U
 
 
 
FN
FQ
36.86°

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  125  -U
U
TRAMO A-B +++ΤFDΤ+

U:U`Ux `U7U
U
Normal   UDUU



+=⇒=
−=⇒=
⇒⋅+−⇒
tNx
tNx
Parax ;í27
;í2:
<9í:;í2 U
CortanteUUQUU



−=⇒=
=⇒=
⇒⋅−⇒
tQx
tQx
Parax 2í67
2í6:
2=í+2í6 U
MomentoUFUU



⋅=⇒=
⋅=⇒=
⇒⋅−⋅⇒
mtMx
mtMx
Paraxx :7
::
2
2=í+
2í6
2
U
nodvocsFUsiU
DIAGRAMA DE ESFUERZOS INTERNOS +→∑→+β⇔+γ∑→[+∆+→+E+θβ∑∴<++
A
B
4 t
R
V
RH
0.96 t/m
1.28 t/m
N
Q
M
2.4 t
2.4 t
3.2 t
3.2 t
4 t.m
(+)
(+)
(+)
(-)
(-)
U
U U
∑βθβ⇒γ→[θ+→+√[⇒γ(⇒,→√(⇒+,⇒+∑βθ,β⇒+δβ+⇔[θ+)→⇔[∑βFUs(dYsóvFUs(aFdsodsFUsoUimUemYYmíU
DUU
tMin
tMax;í2
;í2−=
=
⇒ UUU 0UUUQUU
tMin
tMax2í6
2í6−=
=
⇒ UUUUU0UUUUU UFUU
mtMin
mtMaxM:
M;=
=
⇒ U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  126  -U
U
Ejercicio # 9 
8sUuaSsUmomiatmYUimUsFdYycdyYmíU
1 t
1.5 t
0,5
3
1
4
6
A B
D
C
E
F
3
0.5 t/m
1.5 t/m
U
G = 4 – 3 - 1  = 0 ; Estructura ISOSTATICA 
Paso 1)
U CicyivUSsUYsmccavosFUSsUmuvgvíU
D
C
0.5 t/m
1.5 t/m
H
B
ββββ
R=1.5 t
R=9.12 t
R
V
RH
VA VB
αααα
1 t
1.5 t
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  127  -U
U



=
=
⇒= <<í:cvF
+9í:
9
+
dmoα
α
α
sen
U
βαβ=⇒=
6
7í:
dmo U
tHHH
BB :;í+:,+9í:*+2í<7í++: −=⇒=+−+⇒=

tVVM
BBA6=í9:9,6,*<<í:*+2í<,7í;,*+9í:*+2í<,7í+*7í+,=*+,7*7í+: =⇒=⋅−+−++⇒= ∑
tVVM
AAB+7í;:9,7*7í+,=*+,7í;*7í+,6,*<<í:*+2í<,7í;,*+9í:*+2í<: =⇒=+++−−−⇒= ∑ U
 >DP1>"UU
:+7í;<<í:L+2í<7í+6=í9: =+−−⇒=
∑V U
Paso 2)+Τ]γβ⇒√(⇒+δβ+⇔→θ+β√,→√([⇒βθ+δβ+βθ−,β∑•[θ+(⇒γβ∑⇒[θ+
1.5 t/m
VA
H
B
VB
ββββ
R=1.5 t
R=9.12 t
R
V
RH
y
x
y
x
x
y
x
1 t
1.5 t
y
x
αααα
D
C
0.5 t/m
UUU
U
8sUYsmiatmUyoUcvodYviUMaomiUsoUsiUoySvU UumYmU sYaM(√→√(⇒⋅++
TRAMO A-C 
UUDOMINIO 

 0 < x < 2.5 
Normal   UDUU4U5;í+7Ut 
 vYdmodsUUQUU4U:UdU
FvósodvUFUU4U:UdMóU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  128  -U
U
C
1.5 t
4.15 t
4.15 t
N Q M
4 t
(-)
U
TRAMO B-D +++ΤFDΤ+

U:U`Ux `U;U
Normal   UDUU t6=í9−⇒U
CortanteUUQUU t:;í+⇒U
MomentoUFUU



⋅=⇒=
⋅=⇒=
⇒⋅⇒
mtMx
mtMx
Parax +9í;;
::
:;í+ U
6.38 t
1.04 t
6.38 t
6.38 t
1.04 t
1.04 t
N Q M
6.38 t
1.04 t 4.16 t.m
(-) (+)
(+)
4.16 t.m
4.16 t.m
U
TRAMO D-C +++ΤFDΤ+

U:U`Ux `U9í:=U
U
Normal   UDUU



−=⇒=
−=⇒=
⇒−⇒
tNx
tNx
Para :7í2:=í9
:7í2:
:7í2 U
CortanteUUQUU



=⇒=
−=⇒=
⇒⋅+−⇒
tQx
tQx
Parax <Jí2:=í9
+7í9:
7í++7í9 U
MomentoUFUU



⋅=⇒=
⋅−=⇒=
⇒⋅−⋅+−⇒
mtMx
mtMx
Para
x
x 27í7:=í9
+9í;:
2
7í++7í9+9í;
2
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  129  -U
U
1.04 t
4.16 t.m
C
1.5 t
6.38 t
1.04 t
4.16 t.m
2.05 t
4.16 t
4.16 t.m
N
Q
M
(-)
(-)
(-)
(+)
(+)
2.05 t
6.15 t
2.97 t
8.45 t.m
5.25 t.m
4.16 t.m
4,33
2.05 t
2.97 t
5.25 t.m
6.38 t
U
TRAMO F-E +++ΤFDΤ+

U:U`Ux `U6U
U
Normal   UDUU



−=⇒=
=⇒=
⇒⋅−⇒
tNx
tNx
Parasenx 2;í:6
::
,*7í:
β U
CortanteUUQUU



=⇒=
=⇒=
⇒⋅⇒
tQx
tQx
Parax ;=í+6
::
7í: U
MomentoUFUU



⋅−=⇒=
⋅=⇒=
⇒⋅−⇒
mtMx
mtMx
Para
x 27í26
::
2
7í:
2
U
0.5 t/m
1 t
E
F
N
Q
M
0.24 t
1.48 t
2.25 t.m
(-)
(-)
(+)
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  130  -U
U
 
TRAMO E-C +++ΤFDΤ+

U:U`Ux `U6U
U
Normal   UDUU t7í+−⇒U
CortanteUUQUU t+⇒U
MomentoUFUU



⋅−=⇒=
⋅−=⇒=
⇒⋅−−⇒
mtMx
mtMx
Parax 27í76
27í2:
+27í2 U
C
1 t
1.5 t
1.5 t
2.25 t.m
1 t
1.5 t
2.25 t.m
2.25 t.m
1.5 t
1 t
1 t
1.5 t
5.25 t.m
N Q M1 t
1.5 t 5.25 t.m
2.25 t.m
(-)
(-)
(+)
U
Paso 3)+β∑(−(√→√(⇒+β⇒+β⇔+⇒,δ[+δβ+√[⇒γ∑[⇔ω+⇒,δ[+{<+
C
1.5 t
4.15 t
5.25 t.m
1.5 t
1 t
2.5 t
2.65 t
5.25 t.m
U
U
∑=:HU0UU∑=:VU0UUU∑=:MU
LA ESTRUCTURA ESTA EN EQUILIBRIO. 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
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ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  131  -U
U
Ejercicio # 10  
8sUuaSsUmomiatmYUimUsFdYycdyYmíU
A B
1.5 t/m
0.5 t/m
1 t
1 t
2 t.m
3 2 2 3
4
1
1
C
E
G
F
D
U
G = 4 - 3 – 1   = 0 ; Estructura ISOSTATICA 
Paso 1)
U CicyivUSsUYsmccavosFUSsUmuvgvíU 1 t
1 t
2 t.m
C D
1.5 t
2 t 6 t
H
B
VB
H
A
VA
2.5 t
E
G
F
U
tHHHHH
ABBA7í<:++97í+: −−=⇒=−−−−+⇒= ∑
tVVM
BBA =í+:+:,2*92,6*+,7í*+: −=⇒=⋅−−+−−⇒= ∑ U
tVVM
AAB=í6:2,2*9,6*+,7*+,=*7í2,*+:: =⇒=+−−−−⇒= ∑ U
∑ =⇒=⋅−⋅⇒= tHHV
AAA
IZQ
C M
=7í2:;6:U
UU
tH
B97í9=⇒U
 >DP1>"UU
:=í+2=í6: =−−⇒=
∑V U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  132  -U
U
Paso 2)+Τ]γβ⇒√(⇒+δβ+⇔→θ+β√,→√([⇒βθ+δβ+βθ−,β∑•[θ+(⇒γβ∑⇒[θ+
A B
1.5 t/m
0.5 t/m
1 t
1 t
2 t.m
6.65 t
1.8 t
2.85 t
3.8 t
y
x
y
x
y
x
y
x
y
x
y
x
UUU
 vóvUgmU!sóvFUósocavomSvUYsmiatmYsóvFUyoUmoCiaFaFUuvYUFsccavosFTUYsmiatmoSvUyoUcvodYviUMaomiUsoU
,⇒+⇒,δ[ω+⇒,δ[+{+→∑→+)β∑(−(√→√(⇒⋅++
TRAMO A-C 
UU8sUYsmiatmYmoU2UFsccavosFíU
DOMINIO 

 0 < x < 5 
Normal   UDUU



−=⇒=
−=⇒=
⇒⋅+−⇒
tNx
tNx
Parax 27í27
J7í;:
7í:J7í; U
CortanteUUQUU



=⇒=
=⇒=
⇒⇒
tQx
tQx
Para :7
::
: U
MomentoUFUU



⋅=⇒=
⋅=⇒=
⇒⇒
mtMx
mtMx
Para :7
::
: U
nodvocsFUsiU
DIAGRAMA DE ESFUERZOS INTERNOS +→∑→+β⇔+γ∑→[+∆+→+{+θβ∑∴<++
A
0.5 t/m
x
2.85 t
3.8 t
2.85 t
3.8 t
2.85 t
3.8 t
4.75 t
0 t
2.25 t
0 t
0 t.m
4.75 t
2.25 t
(-)
N
Q
M
1.35 t
1.8 t
C
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  133  -U
U
 
TRAMO B-D UU8sUYsmiatmYmoU2UFsccavosFíU
mtq
mtq
tP
tsenP
VJ2í:
7
9í6
V<9í:
7
=í;
9í6,9í:*9cvF9
=í;,=í:*99
+
+
==
==
===
===
α
α
U
2 t.m
1.8 t
4.24 t
5.43 t
1.83 t
N
Q
M
0.96 t/m
x
0.72 t/m
1.8 t
1.8 t
6 t
P
P
1
6.65 t
6.65 t
5.43 t
0.65 t
1.8 t
9.2 t.m
9.2 t.m
1.83 t
0.56 t
9.2 t.m
1.8 t
0.65 t
1.5 t/m
2.25 t
4.24 t
9.2 t.m
9.36 t.m
4.42
B
(-)
(+)
(+)
(+)
6.65 t
D
U
DOMINIO 
⇔ 0 < x < 5 
Normal   UDUU



=⇒=
=⇒=
⇒⋅−⇒
tNx
tNx
Parax
=6í+7
;6í7:
J2í:;6í7 U
CortanteUUQUU



=⇒=
−=⇒=
⇒⋅+−⇒
tQx
tQx
Parax
79í:7
2;í;:
<9í:2;í; U
MomentoUFUU



⋅=⇒=
⋅=⇒=
⇒−⇒
mtMx
mtMx
Para
x
2í<7
::
2
<9í:2;í;
2
U
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  134  -U
U
TRAMO D-E UU8sUYsmiatmYmoU2UFsccavosFíU
2 t.m
9.2 t.m
1.8 t
0.65 t
D
7.2 t.m
0.65 t
1.8 t
7.2 t.m
0.65 t
1.8 t
3.6 t.m
0.65 t
1.8 t
E
N
Q
M
(+)
(+)
(+)
1.8 t
0.65 t
7.2 t.m
3.6 t.m
3.6 t.m
0.65 t
1.8 t
 
DOMINIO 

 0 < x < 2 
Normal   UDUU t97í:−⇒U
CortanteUUQUU
t=í+⇒U
MomentoUFUU



⋅=⇒=
⋅=⇒=
⇒+−⇒
mtMx
mtMx
Para
9í62
2íJ:
2íJ=í+ U
TRAMO F-E
UU8sUYsmiatmYmoU2UFsccavosFíU
F
1 t
N Q M1 t
1 t.m
x
(-)
(+)
1 t
1 t.m
E
U
DOMINIO 

 0 < x < 1 
Normal   UDUU



=⇒=
=⇒=
⇒⇒
tNx
tNx
Para
:+
::
: U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  135  -U
U
CortanteUUQUU



−=⇒=
−=⇒=
⇒−⇒
tQx
tQx
Para
++
+:
+ U
MomentoUFUU



⋅=⇒=
⋅=⇒=
⇒⇒
mtMx
mtMx
Parax
++
::
+ U
TRAMO G-E
UU8sUYsmiatmYmoU2UFsccavosFíU
1 t N Q M1 t
1 t.m
x
(-)
(+)
1 t
1 t.m
E
G
 
DOMINIO 

 0 < x < 1 
Normal   UDUU



=⇒=
=⇒=
⇒⇒
tNx
tNx
Para
:+
::
: U
CortanteUUQUU



=⇒=
=⇒=
⇒⇒
tQx
tQx
Para
++
+:
+ U
MomentoUFUU



⋅=⇒=
⋅=⇒=
⇒⇒
mtMx
mtMx
Parax
++
::
+ U
TRAMO E-C
UU8sUYsmiatmYmoU2UFsccavosFíU
U
E
3.6 t.m
0.65 t
1.8 t
1 t
1 t.m
1 t
1 t.m
C
3.6 t.m
1.8 t
1.35 t
3.6 t.m
1.35 t
1.8 t
N
Q
M
(+)
(+)
(-)
3.6 t.m
1.8 t
1.35 t
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  136  -U
U
DOMINIO 

 0 < x < 2 
Normal   UDUU 67í+−⇒Ut 
CortanteUUQUU
=í+⇒Ut 
MomentoUFUU



⋅=⇒=
⋅=⇒=
⇒+⋅−⇒
mtMx
mtMx
Parax
:2
9í6:
9í6=í+ U
Paso 3)+β∑(−(√→√(⇒+β⇒+β⇔+⇒,δ[+δβ+√[⇒γ∑[⇔ω+⇒,δ[+{<+
U
C
1.35 t
1.8 t
1.35 t
1.8 t
0 t.m
0 t.m
U
U
∑=:HU0UU∑=:VU0UUU∑=:MU
UUUUUUUUUUUU
=⇔+D5Τ+∞=+=D{5=DP∆+=D+=Q53EΤ+
"ys%vU SsiU moCiaFaFU YsmiatmSvTU uvSsóvFU mMaYómYU lysU
la  ESTRUCTURA  ESTA  EN 
EQUILIBRIO
íU
→∑→+γβ⇒β∑+,⇒→+√[⇒√β√(⇒+2∑→−(√→+δβ+⇔→+→⇔(√→√(⇒+∑γ(√[θ+β⇒+⇔→+)(δ→+βθγ∑,√γ,∑→⇔+)β∑+→⇒β[θ+
SsiUcmuadyivU6U
U
3.9   ANÁLISIS DE ARCOS 
3.9.1 PROCEDIMIENTO DE ANÁLISIS 
=⇒+θγβ+→→∑γ→δ[+→⇔(√→∑β[θ+β⇔+∑[√βδ((β⇒γ[+δβ+→⇒CiaFaFUumYmUdYmtmYUivFUSam%YmómFU
δβ+ )→∑(→√(⇒+ √[∑∑βθ[⇒δ(β⇒γβω+ √[⇒γβ⇔→⇒δ[+ →∑→+ β⇔⇔vU ivFU uYvcsSaóasodvFU SsU moCiaFaFU gmUU
ósocavomSvFU soU ivFU modsYavYsFU mumYdmSvF0U imU SsSycca⇒+ δβ+ ⇔→θ+ −,⇒√([⇒βθ+ δβ+ ⇔[θ+ β⇔ββ⇒γ[θ+
óscCoacvFUFsUYsmiatmYmUemrvUsiUcyóuiaóasodvUSsUivFUθ(2,(β⇒γβθ+→θ[θ<++

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  137  -U
U
PRIMERO.-UIUumYdaYUSsUimUsFdYycdyYmUuimodsmSmTUFsUcvoFdYygsUyoUSam%YmómUSsUcysYuvU
⇔(]∑β+→∑→+(δβ⇒γ(−(√→∑<++
U El sistema de fuerzas.-+→δ[+′,β+θβ+→⇒→⇔(•→⇒+βθγ∑,√γ,∑→θ+⇔→⇒→θω+β⇔+θ(θγβmUSsUMysYtmFUsoU
FyUcvoryodvUuvSYCUFsYUyoUFaFdsómUSsUMysYtmFUumYmisivUvUyoUFaFdsómUSsUMysYtmFU%sosYmisFUsoU
siUuimovíUU
U Las condiciones de isostaticidad.-+δβ⇒γ(−(√→δ[+β⇔+⇒0β∑[+δβ+⇔→θ+(⇒√2⇒(γ→θ+∫+β⇔+⇒0βYvU
SsUimFUscymcavosFUSsUslyaiaeYavUsFdCdacvUlysUcvodasosUsiUFaFdsómUsoUFyUcvoryodvTUFsUdsoSYCoU
sisósodvFU SsU moCiaFaFU umYmU mevYSmYU sFdYycdyYmFU cymoSvU imFU cvoSacavosFU SsU aFvFdmdacaSmSU
θβ→⇒+(2,→⇔βθ+βθγ[+βθ<++≤+=⋅++
U El tipo de estructura.-U voUsiUYsFyidmSvUmodsYavYTUsFdmYsóvFUsoUcvoSacavosFUumYmUmevYSmYU
siUmoCiaFaFUSsUyomUsFdYycdyYmUlysUFsUSsMaosUcvóvU
Isostática.UU
SEGUNDO.-UIuiacmoSvUimFUcvoSacavosFUSsUslyaiaeYavUFveYsUsiUSam%YmómUSsUcysYuvU
iaeYsTUFsUSsdsYóaomoUimFUYsmccavosFUumYmUsocvodYmYUsiUslyaiaeYavUs(dsYovíUU
TERCERO.-UIomiatmoSvUimUsFdYycdyYmUSsUatlyasYSmUmUSsYsc!mUvU acs sYFmUFs%#oUFsmU
siUcmFvUFsUaSsodaMacmoUivFUdYmóvFUlysUuYsFsodsoUcmóeavFUSsUMvYómUsoUimUcmY%mUs(dsYomTUumYmU
lysTUFveYsUcmSmUyovUSsUsiivFTUFsUcvoFdYygmUyoUSam%Y→→+δβ+√,β∑[+⇔(]∑β+(⇒δ(√→⇒δ[+⇔→+→√√(⇒+
δβ+ ⇔→θ+ √→∑2→θ+ βγβ∑⇒→θ+ ′,β+ →√γ0→⇒+ θ[]∑β+ ⇔→+ [∑√(⇒U lysU FsU momiacs,U imFU lysU FsU !meYCoU SsU
slyaiaeYmYUcvoUyoUYsFyidmodsUaodsYovTUaSsodaMacmoSv+β⇒+θγβω+⇔→θ+√[[⇒β⇒γβθ+′,β+δβ−(⇒β⇒+→+⇔[θ+
sisósodvFUóscCoacvFUlysUmcd#moUsoUsiUdYmóvUYsFuscda víUU
CUARTO.-U IuiacmoSvU imFU cvoSacavosFU SsiU slyaiaeYavU sFdCdacvUFsU SsSycsoU imFU
MyocavosFUSsUivFUsisósodvFUóscCoacvFUlysUFsUuYsFsod→⇒+β⇒+√→δ→+γ∑→[ω+∫+→⇔+θ,θγ(γ,(∑+β⇒+θγ→θ+
⇔[θ+ →∑∴βγ∑[θ+ δβ+ )→∑(→√(⇒+ δβ+ ⇔→+ δ(θγ→⇒√(→+ →⇒2,⇔→∑U ^ϕ_ω+ ∑β)(→+ δβθ√[[θ(√(⇒+ δβ+ ⇔[θ+
sisósodvFUSsUimUcmY%mUs(dsYomUvedsoasoSvUimFUóm%oadySsFUYsFuscda mFíUU
QUINTO.-U voUsiUYsFyidmSvUSsiUuyodvUmodsYavYUFsUuYvcsSsYCUmUdYmtmYUsiUSam%YmómUSsU
)→∑(→√(⇒+→∑→+√→δ→+β⇔ββ⇒γ[+β√∴⇒(√[+√[⇒θ(δβ∑→⇒δ[<UU
U Línea baseUSsUimUMysYtmUovYómiTUMysYtmUcvYdmodsUvUóvósodvUMis([⇒→⇒γβ<+∆+→∑γ(∑+δβ+,⇒+
ómYcvUSsUYsMsYsocamTUóaFóvUlysUFsYCUSsUMvYómUSsiUmY√[+β⇒+→⇒∴⇔(θ(θ+√(∑√,⇔→∑+[+→∑→]⇔(√[+
uvYUsiUcymiUFsUdYmtmUimUi'osmUemFsTUFveYsUimUlysUFs+(⇒δ(√→∑∴⇒+⇔[θ+→∑∴βγ∑[θ+δβ+)→∑(→√(⇒+δβ+
imUSaFdmocamUmo%yimYU^ϕ_0UlysUFsUYsimcavomYCoUFveYsUimUi'osmUemFsTUUsoUsiUlysUFsUivcmiatmYCoU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  138  -U
U
imFU óm%oadySsFU SsU ivFU sisósodvFU óscCoacvFU YsFuscda vFU *ovYómiTU cvYdmodsU vU óvósodvU
Mis(avomods,íUU
U Trazo de la variación de los elementos  mecánicos.-  voUivFUuyodvFUsocvodYmSvFUSsiU
A64(.2+)3 +-26Ao3AL 46 (-6 P(-23 + P(-23 3726-oI-)346 .+ y+Ao+mof- )6 641(6At34 =(6 642+AB 
SsMaoaSmUuvYUimFUMyocavosFUSsUivFUsisósodvFUóscCoac34 u+..+)34 46vM- .+ y+Ao+mof- )6 .+ 
SaFdmocamUmo%yimYUcvYYsFuvoSasodsUmiUmYcvíUU
 
Ejercicio # 11 
d626ASo-+A i vA+1om+A .34 6.6S6-234 o-26A-34 )6. 4o%yasodsUmYcvíU
C
A B
1 t/m
2 t
U
G = 4 - 3 – 1   = 0 ; Estructura ISOSTATICA 
Paso 1)
U CicyivUSsUYsmccavosFUSsUmuvgvíU
U
C
R=3 t
2 t
V
H
A
A
V
H
B
B
1,5
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  139  -U
U
U
tHHHHH
ABBA2:2: +−=⇒=−+⇒= ∑
U tVVM
BBA 27í::9,6*2,7í+*6: −=⇒=⋅−−⇒= ∑ U
tVVM
AAB27í6:,6*2,7í;*6,*9: =⇒=−−⇒= ∑ U
∑ =⇒=⋅−−−⇒= tHH
BB
DER
C M
27í::66,27í:=:U
UU
tH
AJ7í+=⇒U
 >DP1>"UU
:27í:627í6: =−−⇒=
∑V U
Paso 2)+Τ]γβ⇒√(⇒+δβ+⇔→θ+β√,→√([⇒βθ+δβ+βθ−,β∑•[θ+(⇒γβ∑⇒[θ+
C
1 t/m
2 t
3.25 t
1.75 t
0.25 t
0.25 t
UUU
U
noUivFUmYcvFUcaYcyimYsFUsFUuYsMsYaeisUydaiatmYUCo%yivFUumYmUSsMaoaYUimFUFsccavosFíUU
TRAMO A-C    
∞→]β[θ+′,β<+
,cvF66*+
6
cvF6
cvF66
2
+
ϕ
ϕ
ϕ ϕ
⋅−⋅=
⋅=
⋅=
⋅−=
R
send
d
d
U
+ ∞→]β[θ+γ→](⇒+′,β+δβ+⇔→+δβθ√[[θ(√(⇒+δβ+−,β∑•→θ+∑βθ,⇔γ→<+
ϕϕ
ϕϕ
ϕ
ϕ
ϕ
ϕ
senF
F
F
senF
F
senF
⋅−=
⋅−=
⋅=
⋅=
⋅=
⋅=
,cvF66*
cvF,cvF66*
cvFJ7í+
J7í+
cvF27í6
27í6
9
7
;
6
2
+
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  140  -U
U
1 t/m
3.25 t
1.75 t
R
SS +
ϕ
M
N
Q
3.25 t
1.75 t
3−3cvFϕ
-2
-+
-;
-6
-7
-9
U
DOMINIO 

 0 < ϕ  < 90º 
Normal   

      ::
762=−++⇒= ∑ FFFNF
N
 
   
ϕϕϕ
2
cvF6J7í+cvF27í: −−−=∴ senN  
U
Cortante  

      ::
9;+=++−⇒= ∑ FFFQF
Q
 
   
ϕϕϕϕcvF6cvFJ7í+27í: sensenQ +−=∴ 
U
Momento  

      :
2
J7í+27í6:
2
=⋅+⋅+⋅−⇒=∑
d
RddMM
S
 
    2
,cvF66*
,6*J7í+,cvF66*27í6
2
ϕ
ϕϕ−
−−−=∴ senM U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  141  -U
U
=⇒+⇔→+θ(2,(β⇒γβ+γ→]⇔→+[θγ∑→[θ+⇔→+)→∑(→√(⇒+δβ+)→⇔vYsFUlysUs(aFdsoUmUivUimY%vUSsiUdYmóvUI5 U
θβ+∑β√[(β⇒δ→+,⇒→+)→∑(→√(⇒+√→δ→+ϖc+
  Normal “N” 
[t] 
Cortante “Q” 
[t] 
Momento “M” 
[t_m] 
:cU 56í27U 5+íJ7U :U
+7cU 56í;<U 5:í==U 5+í:6U
6:cU 56í6;U 5:í:<U 5+í;:U
;7cU 52í<+U :í;;U 5+í2;U
9:cU 52í6<U :í9;U 5:í=:U
J7cU 5+í<7U :í7;U 5:í62U
<:cU 5+íJ7U :í27U :U
TRAMO B-D    
DOMINIO 

 0 <UϕU+ < 90º 
ϕ
M
N
Q
0.25 d
-
+
-2
0.25 t
0.25 t
0.25 t
-;
-6
+
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  142  -U
U
∞→]β[θ+′,β<+
+;
+6
+2
++
cvF27í:
27í:
27í:
cvF27í:ϕ
ϕ
ϕ
ϕ
⋅=
⋅=
⋅=
⋅=
F
senF
senF
F
U
Normal   

      ::
6+=−−⇒= ∑ FFNF
N
 
     
++27í:cvF27í:ϕϕsenN +=∴ 
Cortante  

      ::
;2=+−⇒= ∑ FFQF
Q
 
     
++cvF27í:27í:ϕϕ−=∴ senQ  
Momento  

      :,6*27í:,cvF66*27í::
++=⋅−⋅−+⇒= ∑ ϕϕsenMM
S
 
     
,6*27í:,cvF66*27í:
++ϕϕsenM +⋅−−=∴ U
=⇒+⇔→+θ(2,(β⇒γβ+γ→]⇔→+[θγ∑→[θ+⇔→+)→∑(→√(⇒+δβ+)→⇔vYsFUlysUs(aFdsoUmUivUimY%vUSsiUdYmóvUE5 U
θβ+∑β√[(β⇒δ→+,⇒→+)→∑(→√(⇒+√→δ→+ϖc+
  Normal “N” 
[t] 
Cortante “Q” 
[t] 
Momento “M” 
[t_m] 
:cU :í27U :í27U :U
+7cU :í6+U :í+=U :í+JU
6:cU :í6;U :í:<U :í2JU
;7cU :í67U :U :í6+U
9:cU :í67U 5:í:<U :í2JU
J7cU :í67U 5:í+=U :í+JU
<:cU :í27U 5:í27U :U
 
Paso 3)
UDIAGRAMAS DE ESFUERZOS 
 
 
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  143  -U
U
U ESFUERZO NORMAL 

15°
30°
45°
60°
75°
90°
15°

15°
30°
45°
60°
75°
(-)
(+)
3.25 t
3.49 t
3.34 t
2.91 t
2.39 t
1.967 t
1.75 t
0.25 t
0.31 t
0.35 t
0.35 t
0.34 t
0.31 t
0.25 t
U
U ESFUERZO CORTANTE 

15°
30°
45°
60°
75°
90°
15°

15°
30°
45°
60°
75°
1.75 t
0.88 t
0.09 t
0.44 t
0.64 t
0.54 t
0.25 t
0.25 t
0.18 t
0.09 t
0 t
0.09 t
0.18 t
0.25 t
(-)
(+)
(-)
U
U DIAGRAMA DE MOMENTOS 

15°
30°
45°
60°
75°
90°
15°

15°
30°
45°
60°
75°
(-)
(-)
0 t.m
1.03 t.m
1.40 t.m
1.24 t.m
0.80 t.m
0.32 t.m
0 t.m
0.17 t.m
0.27 t.m
0.31 t.m
0.27 t.m
0.17 t.m
0 t.m
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  144  -U
U
A
B
S
dR
dR
dR
1
2
ϕ
ϕ
45°45°
2 t
Nota.-  =⇒+⇔→+)→∑(→√(⇒+δβ+⇔[θ+δ(→2∑→→θ+δβ+βθ−,β∑•[θ+(⇒γβ∑ovFU*DvYómiTU vYdmodsUgUFvósodv,UcmesU
ósocavomYUlysUovUFvoUYscdmFUimFUlysUFsU moUSaeyrmoS[+β⇒γ∑β+⇔[θ+,⇒γ[θ+δβ+)→∑(→√(⇒ω+θ[⇒+√,∑)→θ+′,β+
FsUimFUveFsY mY'mUósrvYUFaUsFUlysUsiUCo%yivUSsU mYa→√(⇒+→+⇔[+⇔→∑2[+δβ⇔+→∑√[+−,β∑→+→θ+∑βδ,√(δ[ω+[∑+
srsóuivUcmSmU+cí
 
Ejercicio # 12 
βγβ∑(⇒→∑+∫+2∑→−(√→∑+⇔[θ+β⇔ββ⇒γ[θ+(⇒γβ∑⇒[θ+δβ⇔+θ(%yasodsUmYcvíU
U
lU4U+Ut/mU
YmSavU4U2Um 
SU4U2U
2
2
4U2Um 
U
U
 
 
 
 
 
Paso 1)
U CicyivUSsUYsmccavosFUSsUmuvgvíU
U 3Ys amósodsUFsUSsdsYóaomYmUsiU mivYUSsUimUYsFyidmodsUcvYYsFuvoSasodsUmUimUcmY%mUSaFdYaeyaSmUq 
= 1 t/m 
qrR
dsenRdRsendR
qrR
dRdRdR
rdqdsqdR
=
=⇒=
=
=⇒=
⋅=⋅=


2
<:
:
22
+
<:
:
++
cvFcvF
ϕϕϕ
ϕϕϕ
ϕ
U
+ [∑+γ→⇒γ[<+
2
2
2
+
RRR +=U
+ =⇒γ[⇒√βθ<+
tqrR =2=í22==U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  145  -U
U
+ + β→⇔(√β[θ+,⇒+{3+→∑→+γ∑→]→α→∑+√[⇒+→∫[∑+−→√(⇔(δmSU
2 t
H
A
VA
VB
2.828 t
U
U
tHHH
AA2:2: =⇒=−⇒=

U tVVM
BBA
=2=í::,22*22,2*=2=í2: =⇒=+−−⇒= ∑ U
tVVM
AAB
::í2:2=2=í222,22*: =⇒=−−+⇒= ∑ U
 >DP1>"UU
:=2=í:=2=í2::í2: =+−⇒=
∑V U
Paso 2)+Τ]γβ⇒√(⇒+δβ+⇔→θ+β√,→√([⇒βθ+δβ+βθ−,β∑•[θ+(⇒γβ∑⇒[θ+
2 t
H
A
VA
VB
2.828 t
UUU
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  146  -U
U
DOMINIO 

 0 < ϕ  < 45º 
2 t
2 t
M
N
Q
S
S
+
ϕ
2 t
2 t
-2
-+
-;
-6
U
∞→]β[θ+′,β<+
UUUUUUUU
ϕ
ϕ
send
d
⋅=
⋅−=
2
cvF22
+
U
+ ∞→]β[θ+γ→](⇒+′,β+δβ+⇔→+δβθ√[[θ(√(⇒+δβ+−,β∑•→θ+∑βθ,⇔γ→<+
ϕ
ϕ
ϕ
ϕ
senF
F
senF
F
⋅=
⋅=
⋅=
⋅=
2
cvF2
2
cvF2
;
6
2
+
U
DOMINIO 

 0 < ϕ  < 45º 
Normal   

      ::
62=++⇒= ∑ FFNF
N
 
       
ϕϕcvF22−−=∴ senN  
U
Cortante  

      ::
;+=−+⇒= ∑ FFQF
Q
 
       
ϕϕsenQ2cvF2+−=∴  

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  147  -U
U
Momento  

      :22:
+ =−+⇒= ∑ ddMM
S
 
       
,cvF22*2;ϕϕ−+−=∴ senM U
=⇒+ ⇔→+ θ(2,(β⇒γβ+ γ→]⇔→+ [θγ∑→[θ+ ⇔→+ )→∑(→√(⇒+ δβ+ )→⇔vYsFU lysU s(aFdsoU mU ivU imY%vU SsiU dYmóvU
→⇒→⇔(•→δ[+δβ+⌠c+→+ϖc+θβ+∑β√[(β⇒δ→+,⇒→+)→∑(→√(⇒+cmSmU+7c,U
 Normal “N” 
[t] 
Cortante “Q” 
[t] 
Momento “M” 
[t_m] 
:cU 52U 52U :U
+7cU 52í;7U 5+í;+U 5:í<U
6:cU 52íJ6U 5:íJ6U 5+í;9U
;7cU 52í=6U :U 5+í99U
 
DOMINIO 

 45 <UϕU+ < 135º 
A
B
R
M
N
Q
ϕ
α
2 t
2 t
R
-+
-2
-6
-;
-7
-9
2 t
2 t
γ
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  148  -U
U
∞→]β[θ+′,β<+
c;7−=ϕα U
ISsóCF0U
ϕ
ϕsenF
F
⋅=
⋅=
2
cvF2
2
+
UUU U U UUUUU
ϕ
ϕcvF2
2
;
6
⋅=
⋅=
F
senF
U
+ →∑→+⇔→+δβθ√[[θ(√(⇒+δβ+⇔→+−,β∑•→+∑βθ,⇔γ→⇒γβ+θβ∑CíU
γ
γ
αγ
cvF
2V<:
9
7⋅=
⋅=
−=
RF
senRF
UU
+ β∑[++βθ<+
2
2
2
+
:
2
:
+
,cvF+*UUU
UcvF\
RRR
qrdsenqrR
qrsendαqrR
+=
−==
==∫

ααα
α
α
α
U
  Pβ⇒β[θ<+
Normal   

      ::
9;2=+++⇒= ∑ FFFNF
N
 
       
,cvFcvF22*γϕϕRsenN ++−=∴ U
 
Cortante  

      ::
76+=+−+⇒= ∑ FFFQF
Q
 
       
γϕϕRsensenQ −+−=∴2cvF2 U
 
Momento  

      :,
2
*,cvF*22: =+−−+⇒=∑
α
ϕϕ rsenRrrrsenMM
S
 
 
 
=⇒+⇔→+θ(2,(β⇒γβ+γ→]⇔→+[θγ∑→[θ+⇔→+)→∑(→√(⇒+δβ+)→⇔vYsFUlysUs(aFdsoUmUivUimY%vUSsiUdYmóvU
→⇒→⇔(•→δ[+δβ+ϖc+→+φϖc+θβ+∑β√[(β⇒δ→+,⇒→+)→∑(→√(oUcmSmU+7c,U
U
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  149  -U
U
  Normal “N” 
[t] 
Cortante “Q” 
[t] 
Momento “M” 
[t_m] 
;7cU 52í=6U :U 5+í99U
9:cU 52í=:U :í2+U 5+í9:U
J7cU 52íJ2U :í;+U 5+í;6U
<:cU 52í7<U :í7<U 5+í+JU
+:7cU 52í;+U :íJ2U 5:í=6U
+2:cU 52í2+U :í=:U 5:í;6U
+67cU 52U :í=6U :U
 
Paso 3)
UDIAGRAMAS DE ESFUERZOS 
U ESFUERZO NORMAL 

15°
30°
45°
60°
75°
90°
135°
120°
105°
(-)
2 t
2.45 t
2.73 t
2.83 t
2.80 t
2.72 t
2.59 t
2.41 t
2.21 t
2 t
U
U ESFUERZO CORTANTE 
75°
90°
135°
120°
105°
(-)
(+)
2 t
1.41 t
0.73 t
0 t
0.21 t
0.41 t
0.59 t 0.72 t
0.80 t
0.83 t

15°
30°
45°
60°
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  150  -U
U
U DIAGRAMA DE MOMENTOS 

15°
30°
45°
60°
75°
90°
135°
120°
105°
(-)
0 t.m
0.90 t.m
1.46 t.m
1.66 t.m
1.60 t.m
1.43 t.m
1.17t.m
0.83 t.m
0.43 t.m
0 t.m
U
→∑→+γβ⇒β∑+,⇒→+√[⇒√β√(⇒+2∑→−(√→+δβ+⇔→+→⇔(√→√(⇒+mYcvFUsoUimU aSmUsFdYycdyYmiU sYUmos(vFUSsiU
cmuadyivU6U
3.10   TEORIA GENERAL DE ARCOS PARABOLICOS íU 
→∑→+γβ⇒β∑+,⇒→+)(θ(⇒+→θ+√⇔→∑→+θ[]∑β+β⇔+→⇒∴⇔(θ(θ+δsUarcos parabólicosUgUvdYvFUdauvFUSsUmYcvFU
sFUuYsMsYaeisUSsFmYYviimYUyomUdsvY'mU%sosYmiTUumYmUuvSsYUMmcaiadmYUsiUdYmemrvUgUdYmemrmYUSsUómosYmUómFU
βγδ(√→⋅+
M
N
Q
xo
yo
M z
N x
Q y
ϕ
ϕ
X
Y
U
3→+ →⇒γβ∑([∑+ 2∑→−(√→+ ⇒[θ+ ,βθγ∑→+ ,⇒→+ [∑√(⇒+ δβ+ ,⇒→+casYdmU  a%mU FsisccavomSmU soU imU umYdsU
SsYsc!mTUmSsóCFU
N, Q, y M  FvoUivFUsFMysYtvFUcvYYsFuvoSasodsFUmiUFaFdsómUivcmiUx o - yoUTUgUNx, Qy y MzU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  151  -U
U
FvoUivFUcvYYsFuvoSasodsFUmiUFaFdsómU%sosYmiUx – y. =⇒γ[⇒√βθ+∑β→⇔(•→⇒δ[+⇔→+∑[γ→√(⇒+√[∑∑βθ[⇒δ(β⇒γβ+
dsosóvFíU
MM
QNsenQ
QsenNN
z
y
x
=
+−=
+=
ϕϕ
ϕϕ
cvF
cvF
U
>UeasoUuysSsUFsYUs(uYsFmSmUsoUMvYómUómdYacamiíU



















 −
=










z
y
xM
Q
N
sen
sen
M
Q
N
+::
:cvF
:cvF
ϕϕ
ϕϕ U
U ISsóCFTUFaUYsmiatmóvFUsiUmoCiaFaFUSsUyoUuslysCvUFs2β⇒γ[+δ(−β∑β⇒√(→⇔ω+γβ⇒β[θ<+
d x
d y
d s
ϕ
dx
dy
ds
ϕ
U
=⇒γ[⇒√βθ<+
22
yxddds +=UUUUUUU0UUUUUU
ds
dy
sen=
ϕ UUUUUUU0UUUUUUUds
dx
=
ϕcvF U
U U U
ωϕ==
dx
dy
dmo U
3,β2[<+
UU
+
+
vFUUUUUUUU0UUUUUU
+
22
ω
ϕ
ω
ω
ϕ
+
=
+
= csen U
U "vFU mivYsFUvedsoaSvFUumYmUFso
ϕUgUcvFϕ+δβ]β⇒+θβ∑+θ,θγ(γ,(δ[θ+β⇒+⇔→+δ(θ[θ(√(⇒+→γ∑(√(→⇔⋅U
U U
→∑→+γβ⇒β∑+,⇒→+βα[∑+√[∑β⇒θ(⇒+δβ⇔+√→⇔√,⇔[+δβ+→∑√[θ+∫+⇔→+→⇔(√→√(⇒+δβ+⇔→+γβ[∑ →+2β⇒β∑→⇔+δβ+
⇔→θ+(θ→θω+⇔→⇒γβ→[θ+→+√[⇒γ(⇒,→√(⇒+,⇒→+θβ∑(β+δβ+srsóuivFUYsFysidvFíU
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  152  -U
U
Ejercicio # 13 
βγβ∑(⇒→∑+∫+2∑→−(√→∑+⇔[θ+β⇔ββ⇒γ[θ+(⇒γβ∑⇒[θ+δβ⇔+θ(2,(β⇒γβ+→∑√[+→∑→]⇔(√[⋅+
A
(0,0)
P
(4,7)
f(x)
0.5 t/m
1 t
U
U
Paso 1)U CicyivUSsUYsmccavosFUSsUmuvgvíU
1 t
R=3.5  t
3,5m
V
H
A
A
M
7m
4m
U
tHHH
AA 7í6:7í6:−=⇒=+⇒= ∑
U mtMMM
AAA ⋅−=⇒=++⇒= ∑ 27í+9:,;*+,7í6*7í6: U
tVVM
AAP+:,7í6*7í6,27í+9*J,7í6*;:=⇒=−−+−−⇒= ∑ U
UU >DP1>"UU
:++:=−⇒=
∑V U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  153  -U
U
Paso 2)+Τ]γβ⇒√(⇒+δβ+⇔→θ+β√,→√([⇒βθ+δβ+βθ−,β∑•[θ+(⇒γβ∑⇒[θ+
P
(4,7)
f(x)
0.5 t/m
1 t
1 t
3.5 t
16.25 t.m
U
∑β)(→β⇒γβω+δβγβ∑(⇒→[θ+⇔→θ+√[⇒δ(√([⇒βθ+2β[γ∑(√mFUSsUf(x)TUsodvocsFU
::,U>*:TUU3mYmUUUUUUUU0UUUUUUU
2
=⇒++= ccbxaxy U
U 3vYUivUdmodvTU
:f;UcymoSvUUUU0UUUUU2f
2
=⇒=+=⇒+= yxbaxybxaxy U
3vYUivUdmodvU
U:=
=+ba U
U 3mYmUP (4,7), dsosóvFU
UJ;+9 =+ba U
U 3vYUivUdmodvTU
U
2
J
+9
J
2
xxy +−= U
U nodvocsFTU
U
2
J
=
J
f +−== xy
ω U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  154  -U
U
U 3vYUivUdmodvTU
22
2
J
=
J
+
2
J
=
J
+






+−+
+−
=
+
=
x
x
sen
ω
ω
ϕ
U
22
2
J
=
J
+
+
+
+
cvF






+−+
=
+
=
x
ω
ϕ
U
0.5 t/m
1 t
3.5 t
16.25 t.m
R=0.5y
M z
N x
Q y
x
g
U
β√[∑δβ[θ+′,β+⇔→+√[⇒)β⇒√(⇒+δβ+θ(2⇒[θ+β⇒+θβ⇒γ(δ[+[θ(γ()[+βθ<+
M M
N
Q
Q
N
(+)
IZQ DER
U
+ =⇒γ[⇒√βθ<+
27í+97í6
2
7í:
+
7í:7í6
2
−++−=
=
−=
xy
y
M
Q
yN
z
y
x
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  155  -U
U
+ β+⇔→+δ(θ[θ(√(⇒+→γ∑(√(→⇔+θβ+γ(β⇒β<+
z
yx
yxMM
QsenNQ
senQNN
=
+=
−=
ϕϕ
ϕϕ
cvF
cvFU
U 3mYmUsiUSvóaoavU ;:
≤≤xω+γβ⇒β[θ<+
Normal   

 
2
2
2
J
=
J
+
=
J
62
J






+−+

=
x
xx
N
 
 
Cortante  

     
2
2
2
J
=
J
+
+
2
J
=
J
;
J
62
J
7í6






+−+
+












+−





−+
=
x
xxx
Q
 
       
Momento  

      27í+9
2
J
+9
J
7í6
2
J
+9
J
2
7í:
2
2
2
−+





+−+





+−−= xxxxxM  
 
=⇒+⇔→+θ(2,(β⇒γβ+γ→]⇔→+[θγ∑→[θ+⇔→+)→∑(→√(⇒+δβ+)→⇔vYsFUlysUs(aFdsoUmUivUimY%vUSsiUdYmóvU
momiatmSvíU
Distancia 
“m”
 
Normal “N” 
[t] 
Cortante “Q” 
[t] 
Momento “M” 
[t_m] 
:U :U 6í9;U 5+9í27U
:í9JU 5:í+9U 2í92U 5=í<7U
+í66U 5:í6+U +í=6U 57í+:U
2U 5:í6<U +í+6U 52íJJU
2í9JU 5:í7+U :í<7U 5+í;=U
6í66U 5:í;2U :í<+U 5:í9=U
;U :U +U :U
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  156  -U
U
Paso 3)UDIAGRAMAS DE ESFUERZOS 
U ESFUERZO NORMAL 
0.67m 1.33m 2.0m 2.67m 3.33m 4m0m
0 t
0.16 t
0.31 t
0.39 t
0.51 t
0.42 t
0 t
(-)
U
U ESFUERZO CORTANTE 
3.64 t
2.62 t
1.83 t
1.13 t
0.95 t
0.91 t
1 t
0.67m1.33m 2.0m 2.67m3.33m 4m0m
0 t
0 t
(+)
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  157  -U
U
U DIAGRAMA DE MOMENTOS 
0.67m 1.33m 2.0m 2.67m 3.33m 4m0m
0 t.m
16.25 t.m
8.95 t.m
5.10 t.m
2.77 t.m
1.48 t.m
0.68 t.m
(-)
U
Nota.-  0- .+ y+Ao+mof- )6 .34 )o+vA+S+4 )6 641(6At34 o-26AovFU*DvYómiTU vYdmodsUgUFvósodv,UcmesU
ósocavomYUlysUovUFvoUYscdmFUimFUlysUFsU moUSaeyrmoS3 6-2A6 .34 P(-234 )6 y+Ao+mof-L 43- m(Ay+4 =(6 
FsUimFUveFsY mY'mUósrvYUFaUsFUlysUimUSaFdmocamUSsU +Ao+mof- + .3 .+Av3 )6. +Am3 1(6A+ S+4 A6)(mo)3L P3YU
srsóuivUcmSmU:í+míU
Ejercicio # 14 
d626ASo-+A i vA+1om+A .34 6.6S6-234 o-26A-34 )6. 4ovyasodsUmYcvUsiaudacvíU
A(0,0) B(6,0)
C(3,2)
X
Y
1 t/m
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  158  -U
U
U
Paso 1)U CicyivUSsUYsmccavosFUSsUmuvgvíU
C(3,2)
R=3 t
H
A
VA
H
B
VB
+í7Uó
U
 
::=+⇒=
∑ BAHHH U U
tVVM
BBAJ7í::9,7í+*6:=⇒=−⇒= ∑ U
tVVM
AAB27í2:,7í;*69:=⇒=−⇒= ∑ U
tHHM
BB
DER
C +27í+:2,J7í:*6:−=⇒=−−⇒= ∑ U
[∑+γ→⇒γ[<+
tH
A+27í+= U
 >DP1>"UU
:J7í:627í2:=+−⇒=
∑V U
Paso 2)+Τ]γβ⇒√(⇒+δβ+⇔→θ+β√,→√([⇒βθ+δβ+βθ−,β∑•[θ+(⇒γβ∑⇒[θ+
X
Y
1 t/m
1.125 t
2.25 t
1.125 t
0.75 t
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  159  -U
U
+ βγβ∑(⇒→[θ+⇔→θ+√[⇒δ(√([⇒βθ+2β[γ∑(√→θ+δβ+⇔→+√,∑)mUsi'udacm.U
xxy
yx
9
6
2
+
;<
,6*
UUUUUUsiauFs
2
;2
+−=⇒=+

⇔ U
U 3vYUivUdmodvTU
xx
x
y
96
92
f
2
+−
+−
==ω U
X
1.125 t
2.25 t
M z
N x
Q y
U
U
+ β√[∑δβ[θ+′,β+⇔→+√[⇒)β⇒√(⇒+δβ+θ(2⇒[θ+β⇒+θβ⇒γ(δ[+[θ(γ()[+βθ<+
M M
N
Q
Q
N
(+)
IZQ DER
U
+ =⇒γ[⇒√βθ<+
x
x
yM
xQ
tN
z
y
x 27í2
2
+27í+
27í2
UU+27í+
2
+−−=
−=
−=
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  160  -U
U
+ D,β)→β⇒γβ+δβ+⇔→+δ(θ[θ(√(⇒+→γ∑(√(→⇔+θβ+γ(β⇒β<+
z
yx
yxMM
QsenNQ
senQNN
=
+=
−=
ϕϕ
ϕϕ
cvF
cvFU
U 3mYmUsiUSvóaoavU 6:
≤≤xω+γβ⇒β[θ<+
DvYómiUUU

 
( ) ( )
2
2
2
2
9296
,92,*27í2*96J7í6
+−++−
+−−−+−−
=
xxx
xxxx
N
 
 
Cortante  

     
( )( )( )
( ) ( )
2
2
2
2
9296
9627í292+27í+
+−++−
+−−++−−
=
xxx
xxxx
Q  
 
 
FvósodvUU⇔
      x
x
xxM 27í2
2
9
6
2
+27í+
2
2
+−





+−−= U
=⇒+ ⇔→+ θ(2,(β⇒γβ+ γ→]⇔→+ [θγ∑→[θ+ ⇔→+ )→∑(→√(⇒+ δβ+ )→⇔vYsFU lysU s(aFdsoU mU ivU imY%vU SsiU dYmóvU
momiatmSvíU
Distancia 
“m”
 
Normal “N” 
[t] 
Cortante “Q” 
[t] 
Momento “M” 
[t_m] 
:U 52í27U 5+í+27U :U
+U 5+í9U :í7U :í:JU
2U 5+í+7U :U :í6=U
6U 5+í+27U 5:íJ7U :U
U
+ →∑→+β⇔+→⇒∴⇔(θ(θ+δβ⇔+θβ2,⇒δ[+γ∑→[ω+γβ⇒β[θ<+

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  161  -U
U
X
1 t/m
1.125 t
2.25 t
M z
N x
Q y
U
=⇒γ[⇒√βθ<+
( ) xxyM
tQ
tN
z
y
x
27í27í+6+27í+
UUUJ7í:UU
UU+27í+
+−−−=
−=
−=
U
U 3mYmUsiUSvóaoavU 96≤≤xω+γβ⇒β[θ<+
Normal   

 
( )
( ) ( )
2
2
2
2
9296
92J7í:96J7í6
+−++−
+−−+−−
=
xxx
xxx
N
 
Cortante  

     
( )()( )
( ) ( )
2
2
2
2
9296
927í292+27í+
+−++−
+−++−−
=
xxx
xxx
Q
 
 
Momento  

      ( ) xxxxM 27í27í+69
6
2
+27í+
2
+−−





+−−= U
=⇒+ ⇔→+ θ(2,(β⇒γβ+ γ→]⇔→+ [θγ∑→[θ+ ⇔→+ )→∑(→√(⇒+ δβ+ )→⇔vYsFU lysU s(aFdsoU mU ivU imY%vU SsiU dYmóvU
momiatmSvíU
Distancia 
“m”
 
Normal “N” 
[t] 
Cortante “Q” 
[t] 
Momento “M” 
[t_m] 
6U 5+í+27U 5:íJ7U :U
;U 5+í2JU 5:í;=U :í92U
7U 5+í67U :U :í<6U
9U 5:íJ7U 5+í+27U :U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  162  -U
U
Paso 3)UDIAGRAMAS DE ESFUERZOS 
U ESFUERZO NORMAL 
6m5m4m3m2m1m
0 t
2.25 t
1.60 t
1.15 t
1.125 t
1.27 t
1.35 t
0.75 t 0 t
(-)
U
U
U ESFUERZO CORTANTE 
1m 2m 3m 4m 5m 6m
0 t
(-)
(+)
(-)
(+)
1.125 t
0.5 t 0 t
0.75 t
0.48 t
0 t
1.125 t
U
U
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  163  -U
U
U DIAGRAMA DE MOMENTOS 
1m 2m 3m 4m 5m 6m
0 t.m
0.07 t.m
(+)
(-)
0.38 t.m
0 t.m
0.62 t.m
0.93 t.m
U
U
U
Nota.-  0- .+ y+Ao+mof- )6 .34 )o+vA+S+4 )6 641(6At34 o-26AovFU*DvYómiTU vYdmodsUgUFvósodv,UcmesU
ósocavomYUlysUovUFvoUYscdmFUimFUlysUFsU moUSaeyrmoS3 6-2A6 .34 P(-234 )6 y+Ao+mof-L 43- m(Ay+4 =(6 
FsUimFUveFsY mY'mUósrvYUFaUsFUlysUimUSaFdmocamUSsU +Ao+mof- + .3 .+Av3 )6. +Am3 1(6A+ S+4 A6)(mo)3L P3YU
srsóuivUcmSmU:í+míU
U
3.11  ANÁLISIS DE ESTRUCTURAS MIXTAS íU 
 
86 A61o6A6 + .+ m3S7o-+mof- )6 23)+4 .+4 642A(m2(A+FUgmUmomiatmSmFTUSvoSsUsiUuYvcsSaóasodvUSsU
cmicyivUSsUcmSmUyovUSsUivFUdYmóvFTUgmUFsmoUsFdvFUYscdvFUvUmYcvFUSsesYCoUFsYUmomiatmSvFUSsUómosYmU
aoSsusoSasodsUcvóvUgmUFsU!mU aFdvU!mFdmUm!vYmíUU
3mYmUcvociyaYUsiUmoCiaFaFUSsUsFdYycdyYmFTUuimodsmóv4 + m3-2o-(+mof- .+ 43.(mof- )6 656SP.34 
YsFysidvFUSsUsFdYycdyYmFUóa(dmFíU
 
Ejercicio # 15 
d626ASo-+A i vA+1om+A .34 6.6S6-234 o-26A-34 )6 .+ 4a%yasodsUsFdYycdyYmUóa(dmíU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  164  -U
U
E
C
B
A
D
q=1.5 t/m
q =0.5 t/m
1
2 t
1 t
1,53 3
1,5
2,5
1
U
Paso 1)U CicyivUSsUYsmccavosFUSsUmuvgvíU
3Ys amósodsUFsUSsdsYóaomYmUsiU mivYUSsUimUYsFyidmodsUcvYYsFuvoSasodsUmUimUcmY%mUSaFdYaeyaSmUSsU
q = 1.5 t/mTUlysUmcd#mUusYusoSacyimYósodsUmiUmYcvíU
dR
dR
dR
H
V
ϕ
ϕ

ds
R
U
22
VHRRR += U
+ =⇒γ[⇒√βθ<+
ϕqrdqdsdR == U
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  165  -U
U
+ [∑+⇔[+γ→⇒γ[<+
:UcvF
cvF
cvF
:
==
=
=

π
ϕϕ
ϕϕ
ϕ
dqrR
dqrdR
dRdR
H
H
H
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
qrdqrsenR
dqrsendR
dRsendR
V
V
V
2U
:
==
=
=

π
ϕϕ
ϕϕ
ϕ
U
=⇒γ[⇒√βθ<+
tR7í;,7í+,*7í+*2== U
U U
+ β](δ[+ →+ ⇔→+ θ(βγ∑ →+ δβ+ ⇔→+ √→∑2→+ δ(θγ∑(],(δ→+ →−(∑→óvFU lysU imU YsFyidmodsU SsU imU cmY%mU
SaFdYaeyaSmUusYusoSacyimYUmiUmYcvUumFmUuvYUsiUsrsU^g_íU
U
∆+√[⇒γ(⇒,→√(⇒+δβγβ∑(⇒→[θ+⇔→+∑βθ,⇔γ→⇒γβ+δβ+⇔→+√→∑2mUSaFdYaeyaSmUlysUmcd#mUmUivUimY%vUSsiUU
dYmóvUE – C.U
E C
q =0.5 t/m
1
3
R
1
U
() tLqRUU7í+67í:
++ === U
+ 3→+⇔ ⇒β→+δβ+→√√(⇒+δβ+
+UsFUcvaocaSsodsUcvoUimUYscdmUlysUumFmUuvYUsiUdmóvUE – C.U
+ F[θγ∑→[θ+β⇔+δβγ→⇔⇔β+δβ+⇔→θ+→∑γ(√,⇔→√([⇒βθ<+
E
D
U
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  166  -U
U
+ ∆ϕ[∑→+)β→[θ+⇔→+βθγ∑,√γ,∑→+β⇒+⋅{⋅3⋅+
E
C
B
A
D
2 t
1 t
R=4.5t
H
A
VA
H
B
VB
VC
R =1.5t
1
U
∆⇔(√→⇒δ[+⇔→θ+β√,→√([⇒βθ+δβ+β′,(⇔(]∑([+γβ⇒β[θ<+
:+7í+2:=−+++⇒=
∑ BAHHH U U
()() () :7íJ++67í2+27í+7í;:=−−−−⇒= ∑ CBBAVVHM U
()()()() :7í;7í6+7í+27í27í+7í+7í;7í26:=−−++−+⇒= ∑ CAABVHVM U
U
U IuiacmoSvUimFU2UscymcavosFUsFuscamisFUlysU%sosYmoUimFUmYdacyimcavosFTUYsFvi sóvFUsiUFaFdsómTU
usYvUuYs amósodsUU
() tVVM
CC
DER
E 66í::6++:−=⇒=−−⇒= ∑ U
() tHHM
BB
ABAJO
D =í::7í2+2:−=⇒=−−⇒= ∑ U
U
[∑+⇔[+γ→⇒γ[<++
tH
A Jí+−= UU tV
A:=6í2= UU tV
BJ7í2= U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  167  -U
U
E
C
B
A
D
2 t
1 t
R=4.5t
R =1.5t
1
1.7 t
2.083 t
2.75 t
0.8 t
0.33 t
U
 >DP1>"UU
:66í:J7í27í;:=6í2:=−+−⇒=
∑V U
Paso 2)+Τ]γβ⇒√(⇒+δβ+⇔→θ+β√,→√([⇒βθ+δβ+ESFUERZOS INTERNOS 
TRAMO A – D +++ΤFDΤ+

U:U`Ux `UgU
U
A
M
N
Q
R
-6
-;
-2
-+
-9
-7
1.7 t
2.083 t
γ
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
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ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  168  -U
U
∞→]β[θ+′,β<+
2V
cvF++=í6
cvF22ϕγ
ϕ
ϕ=
−=
−=
R
qrR
U
+ ∞→]β[θ+γ→](⇒+′,β+δβ+⇔→+δβθ√[[θ(√(⇒+δβ+−,β∑•→θ+∑βθ,⇔γ→<+
2VcvF
2V
cvFJí+
Jí+
:=6í2
cvF:=6í2
9
7
;
6
2
+
ϕ
ϕ
ϕ
ϕ
ϕ
ϕ
⋅=
⋅=
⋅=
⋅=
⋅=
⋅=
RF
senRF
F
senF
senF
F
U
"ys%vTUumYmUsiUSvóaoavUSsU:U`Ux `UgTUSsiUmYcvUSsiUdmóvUA – D θβ∑∴<+
Normal   

      ::
76+=+−+⇒= ∑ FFFNF
N
 
     
2
cvF++=í6Jí+cvF:=6í2
ϕ
ϕϕϕsensenN ⋅−−+−=∴ 
CortanteUU

      ::
9;2=+−−⇒= ∑ FFFQF
Q
       
2
cvFcvF++=í6cvFJí+:=6í2
ϕ
ϕϕϕ⋅−−+=∴ senQ  
Momento  

      ( ) ( ) :Jí+cvF:=6í2
2
: =−−−+⇒=∑ ϕϕ
ϕ
rsenrrRrsenMM
S
 
      ( ) ϕϕ
ϕ
ϕ sensenM 77í2cvF++27í6
2
cvF+JJí; +−+⋅−−=∴ U
U
=⇒+⇔→+θ(2,(β⇒γβ+γ→]⇔→+[θγ∑→[θ+⇔→+)→∑(→√(⇒+δβ+βθ−ysYtvFUlysUs(aFdsoUmUivUimY%vUSsiUdYmóvUIU
I+⋅+
Distancia 
“m”
 
Normal “N” 
[t] 
Cortante “Q” 
[t] 
Momento “M” 
[t_m] 
:cU 52í:=U +íJU :U
+7cU 5+í97U +í9U :í97U
6:cU 5+í29U +í6<U +í2;U
;7cU 5:í<6U +í:=U +íJ6U
9:cU 5:í9;U :íJ+U 2í:=U
J7cU 5:í79U :í2=U 2í2=U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
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ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  169  -U
U
<:cU 5:í77U 5:í+JU 2í6U
+:7cU 5:í97U 5:í9:U 2í+7U
+2:cU 5:í=9U 5:í<<U +í=;U
+67cU 5+í+9U 5+í62U +í6=U
+7:cU 5+í7;U 5+í79U :í=+U
+97cU 5+í<JU 5+í9=U :í+JU
+=:cU 52í;+U 5+íJ:+U 5:í;<U
U
U
DIAGRAMAS DE ESFUERZOS 
U ESFUERZO NORMAL 

15°
30°
45°
60°
75°
90° 180°
165°
150°
135°
120°
105°
(-) (-)
1.65 t
1.26 t
0.93 t
0.64 t
0.56 t
0.55 t
0.65 t
0.86 t
1.16 t
1.54 t
1.97 t
2.41 t
U
U ESFUERZO CORTANTE 

15°
30°
45°
60°
75°
90°
180°
165°
150°
135°
120°
105°
(+)
(-)
1.7 t
1.6 t
1.39 t
1.08 t
0.71 t
0.28 t
0.17 t
0.60 t
0.99 t
1.32 t
1.56 t
1.68 t
1.701 t
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  170  -U
U
U DIAGRAMA DE MOMENTOS 

15°
30°
45°
60°
75°
90° 180°
165°
150°
135°
120°
105°
0 t.m
0.65 t.m
1.24 t.m
1.73 t.m
2.08 t.m
2.28 t.m
2.3 t.m
2.15 t.m
1.84 t.m
1.38 t.m
0.81 t.m
0.17 t.m
0.49 t.m
(+)
U
3mYmUsiUmoCiaFaFUSsUemYYmFUYscvYSsóvFUlysUimUcvo so√(⇒+δβ+θ(2⇒[θ+β⇒+θβ⇒γ(δ[+[θ(γ()[+βθ<+
M M
N
Q
Q
N
(+)
IZQ DER
U
TRAMO B-D +++ΤFDΤ+

U:U`Ux `U+í7U
U
Normal   UDUU
tJ7í2−⇒ U
CortanteUUQUU
t=í:⇒ U
MomentoUFUU



⋅=⇒=
⋅=⇒=
⇒⇒
mtMx
mtMx
Parax
2í+7í+
::
=í: U
ΤFDΤ+

U+í7U`Ux `U2í7U
U
Normal   UDUU
tJ7í2−⇒ U
CortanteUUQUU
t2í+2=í:−=−⇒ U
MomentoUFUU
( )



⋅=⇒=
⋅=⇒=
⇒−−⇒
mtMx
mtMx
Paraxx
:7í2
2í+7í+
7í+2=í: U
2 t
2.75 t
0.8 t
2.75 t
1.2 t
(-)
(+)
(+)
(-)
N Q M
2.75 t
0.8 t
1.2 t
1.2 t.m
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  171  -U
U
TRAMO D-E +++ΤFDΤ+

U:U`Ux `U+í7U
D
2.414 t
1.7 t
0.496 t.m
2.75 t
1.2 t
0.496 t.m
0.5 t
0.33 t
0.496 t.m
0.5 t
0.33 t
N
Q
M
(+)
(+)
(-)
0.5 t
0.33 t
0.496t.m
0.5 t
0.33 t
U
Normal   UDUU



=⇒=
=⇒=
⇒⇒
tNx
tNx
Para
7í:7í+
7í::
7í: U
CortanteUUQUU



=⇒=
=⇒=
⇒⇒
tQx
tQx
Para
66í:7í+
66í::
66í: U
MomentoUFUU



⋅=⇒=
⋅−=⇒=
⇒+−⇒
mtMx
mtMx
Parax
:7í+
;<9í::
66í:;<9í: U
TRAMO F-C 
+++ΤFDΤ+

U:U`Ux `U+U
1 t
N Q M1 t
1 t.m
x
(-)
(+)
1 t
1 t.m
C
F
U
Normal   UDUU



=⇒=
=⇒=
⇒⇒
tNx
tNx
Para
:+
::
: U
CortanteUUQUU



−=⇒=
=⇒=
⇒−⇒
tQx
tQx
Para
++
::
+ U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  172  -U
U
MomentoUFUU



⋅=⇒=
⋅=⇒=
⇒⇒
mtMx
mtMx
Parax
++
::
+ U
TRAMO C-E +++ΤFDΤ+

U:U`Ux `U6U
0.5 t
0.5 t
0.33 t
E
1 t.m
1 t0.33 t
N
Q
M
(+)
(+)
1 t.m
0.33 t
1 t
q =0.5 t/m
1
(-)
(+)
U
Normal   UDUU



=⇒=
−=⇒=
⇒+−⇒
tNx
tNx
Parax
7í:6
+:
7í:+ U
CortanteUUQUU



=⇒=
=⇒=
⇒⇒
tQx
tQx
Para
66í:6
66í::
66í: U
MomentoUFUU



⋅=⇒=
⋅=⇒=
⇒−⇒
mtMx
mtMx
Parax
:6
+:
66í:+ U
Paso 3)+β∑(−(√→√(⇒+β⇒+β⇔+⇒,δ[+δβ+√[⇒γ∑[⇔ω+⇒,δ[+=<+
U
0.5 t
0.33 t
0.5 t
0.33 t
E
U
∑=:H U0UU∑=:VU0UUU∑=:M U
=⇔+D5Τ+∞=+=D{5=DP∆+=D+=Q53EΤ+
"ys%vUSsiUmoCiaFaFUYsmiatmSvTUuvSsóvFUmMaYómYUlysU
la ESTRUCTURA ESTA EN 
EQUILIBRIO
íU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  173  -U
U
3.12   EJERCICIOS PROPUESTOS. 
U 8sUuaSsUSsdsYóaomYUimFUscymcavosFUgUSam%YmómFUSsUsFMysYtvFUumYmUivFUFa%yasodsFUsrsYcacavFíU
Problema #1 
q=1 t/m
3
M

H
U
Respuesta:        UUíJ7í:0+ mtMtV == U
(→2∑→→++δβ+[β⇒γ[θ+
(-)
0.75 t.m
M
U
Problema #2 
 
βθ[⇔)β∑+β⇔+θ(2,(β⇒γβ+βαβ∑√(√([+[∑+β⇔+γ[δ[+∑β⇔→√([⇒→⇔+∫+[∑+β⇔+γ[δ[+−,⇒√([⇒→⇔⋅+
222VA VB
0.5 t/m
2 t.m
A B
U
Respuesta:       
tVtV
BAJ7í:UUUUU0UUUUU27í:== U
(→2∑→→+δβ+[β⇒γ[θ<+

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  174  -U
U
2 t.m
2 t.m
0.5 t.m
0.06 t.m
1
(-)
U
Problema #3 
213
3,5
3,5
2 t.m
H
A
VA
A B
2 t
VB
1.5 t/m
C D E
F
G
U
Respuesta:       
tV
tVtH
B
AA
2<í6
2<í2UUUUU0UUUUUJ7í+
=
==
U
(→2∑→→++++γ∑→[+++++∆+I+{+
N
Q
M
2.29 t
1.75 t
8.17 t.m
(+)
(+)
(+)
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  175  -U
U
 
Problema #4 
A B
1 t/m
0.5 t.m
1 t
2 t
D
F
E
E G
2,5
1,5
33
2
4
U
Respuesta:       
tVtH
tVtH
BB
AA
JJí:UUUUU0UUUUU6í:
26í2UUUUU0UUUUU2í2
==
==
U
(→2∑→→++++γ∑→[+++++∆+I++
1 t/m
D
2.23
2.19
X
X
N
Q
M
-2.23 t
2.19 t
0.31 t
2.38 t.m
1.92 t.m
(-)
(+)
(-)
(+)
U
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  176  -U
U
Problema #5 
A
B
H
V
A
VB
A
2 t
C D
132
3
1
0.8 t/m
U
Respuesta:       
U72í+
72í6UUUUU0UUUUU2í6
tV
tVtH
B
AA
=
==
U
(→2∑→→++++γ∑→[+++++{+I++
BC D
(-)
(-)
(-)
N
Q
M
3.2 t
1.52 t
4.56 t.m
U
U
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  177  -U
U
Problema #6 
R=2.5 m 
C
A B
1 t/m
0.5 t
V
H
A
A
V
H
B
B
30°
R
U
Respuesta:       
tVtH
tVtH
BB
AA
97=í:UUUUU0UUUUU97=í:
6;2í2UUUUU0UUUUU97=í:
==
==
U
(→2∑→→+D++γ∑→[+++++∆+I+{+

15°
30°
45°
60°
75°
90°
(-)
2.34 t
2.35 t
2.07 t
1.25 t
0.87 t
0.63 t
0.66 t
1.63 t
U
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  178  -U
U
0.5m1.0m1.5m2.0m2.5m3m0m
0 t.m
1.25 t.m
2.0 t.m
2.25 t.m
2.0 t.m
1.25 t.m
(+)
0.5m1.0m1.5m2.0m0m
0 t.m
0.03 t.m
0.082 t.m
0.090 t.m
(+)
Problema #7UU
0.5 t/m
VA
VB
Arco Parabolico
A(0,0)
B(3,5)
U
Respuesta:       
tVtV
BA6UUU0UUU6U==U
(→2∑→→++++F+++γ∑→[+++++∆+I+E+
Problema #8 
A(0,0)
VA
B(4,0)
VB
C(2,3)
H
A
H
B
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  179  -U
U
Respuesta:       
tVtH
tVtH
BB
AA
66í:UUUUU0UUUUU22í:
9Jí:UUUUU0UUUUU22í:
==
==
U
8sU%YmMacmUsiUSam%YmómUU^F_UUdYmóvUIUIU UU
Problema #9 
R=2.5 m 
C D
0.3 t/m 0.2 t
0.4 t.m
0.3 t
H
V
B

A
VA
B
2
34
1,5
1,5
U
Respuesta:       
tVtH
tV
BB
A
+;í:UUUUU0UUUUU6í:
099í:U
==
=
U
(→2∑→→+D++γ∑→[+++++∆+I+{+
N
Q
M
0.14 t
0.3 t
0.45 t.m
(+)
(-)
(+)
(-)
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  180  -U
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3.13   EVALUACION DIAGNOSTICO DEL CAPITULO. 
 
 
3+A+  A6+.ot+A  (-+  6y+.(+mof-  )o+v-342om3  A616A6-26 miU uYsFsodsU cmuadyivTU FsU uYvuvosU miU
sFdySamodsUYsFuvoSsYUimFUFa%yasodsFUuYs%yodmFíU
U  ymisFUFvoUivFUsisósodvFUSsUivFUsFMysYtvFUaodsYovFXU
U l(+. 64 .+ )61o-omof- )6 641(6At3 D3AS+.X 
U  vóvUFsUSa aSsUsiUmoCiaFaFUSsUsFdYycdyYmFXU
U l(+.64 43- .34 SI23)34 P+A+ 6. +-B.o4o4 )6 yov+4X 
U l(+. 64 .+ )o16A6-mo+ 6-2A6 6. +-B.o4o4 P3A 6. SI23)3 A6.+mo3-+. i 6. SI23)3 1(-mo3-+.X 
U 0- 6. +-B.o4o4 )6 PfA2om34 =(6 SI23)3 )6 +-B.o4o4 6FUómFUmcvoFsrmeisUgUuvYUlysXU
U 0- =(6 m3-4o426 .+ y6Ao1om+mof- )6 641(6At34 o-26A-34 6- PfA2om34 i u+42+ m(+-)3 64 +m6P2+7.6 
(-+ y+Ao+mof- 6- .34 A64(.2+)34X 
U 08P.o=(6 .+ 263Ab+ v6-6A+. )6 +Am34 P+A+7f.om34X 
U
U 3mYmU cvociyaYU sFdsU Sam%ovFdacvU FsU uaSsU SsdsYóaomYUimFU YsmccavosFU SsU muvgvU gU %YmMacmYU ivFU
Sam%YmómFUSsUsFMysYtvFUSsUimFUFa%yasodsFUMa%yYmFíU
Prob # 1 
44
2
2
0.8 t.m
0.5 t.m

A
D
C
E
U
 
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  181  -U
U
Prob #2 
B
0.5 t/m
A
0.8 t
0.6 t
26
3
4
2
C
D
U
Prob #3 
A
B
0.5 t/m
0.8 t
C
1
26
3
U
U
U
 
 
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  182  -U
U
 
 
 
 
CAPITULO 4  
U
U
U
U
U
U
ARMADURAS (CERCHAS) 
U
U
U
U
4.1   OBJETIVO GENERAL. 
0. 642()o+-26 P(6)6 m3-m6P2(+.ot+A .+ 1(-mof- )6 (-mUmYómSyYmTUivFUdauvFUSsUmYómSyYmFUgUFyU
+P.om+mof-n 08uo76 )642A6t+4 P+A+ A6+.ot+A 6. mB.m(ivUSsUsFMysYtvFUaodsYovFUgUs(dsYovFUsoUimUmYómSyYmíU
U
4.2 OBJETIVOS ESPECIFICOS. 
e. 26ASo-+A 6426 m+Po2(.3 6. 642()o+-26 P3)ABa 
U )SsodaMacmYUmYómSyYmFUaFvFdCdacmFUsU!ausYsFdmdacmFíU
U e)=(oAoA u+7o.o)+)64 P+A+ +P.om+A )oy6A434 SI23)34 PmYmUSsdsYóaomYUivFUsFMysYtvFUaodsYovFUgU
s(dsYovFUsoUivFUóasóeYvFíU
U 3ysSsUYscvYSmYUyoUdauvUSsUmYómSyYmUumYmUcmSmUcmFvíU
U
U
4.3   ARMADURAS. 
 
&omUcsYc!mUuysSsUSsMaoaYFsUcvóvUyomUsFdYycdyYmUcvóuysFdmUSsUyoUo#ósYvUSsUsisósodvFUvU
emYYmFUyoaSvFUsoUFyFUs(dYsóvFUuvYUósSavUSsUumFmSvYs4 4o- 1Aommof- P+A+ 13AS+A (- +AS+tf- Abvo)3n 
"mFUMysYtmFUs(dsYomFUgUYsmccavosFUFsUFyuvosUlysUsFdCoUsoUsiUóaFóvUuimovUSsUimUsFdYycdyYmUgUU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  183  -U
U
mcd#moUFvimósodsUFveYsUivFUumFmSvYsFíUISsóCFTUFsUFyuvosUlysUcmSmUyovUcvaocaSsUcvoUimUi'osmUlysU
yosU ivFU csodYvFU SsU ivFU oySvFU SsU FyFU s(dYsóvFU gU lysUsiU usFvU SsU cmSmU emYYmU sFU SsFuYscameisU soU
m3SP+A+mof- m3- .+4 1(6At+4 6826A-+4 =(6 +m2M+- 437A6 .+ m6Amu+n d6 .+4 m3-)omo3-64 +-26Ao3A64 46 
SacsU lysU cmSmU emYYmU SsU yomU csYc!mU sFU yoU sisósodvU FvósdaSvU mU SvFU MysYtmFU gU FyrsdvU FvimósodsU mU
1(6At+4 +8o+.64 )oA6m2+4 *2A+mmof- 3 m3SPA64of-Cn 0iUmoCiaFaFUcvóuisdvUSsUyomUcsYc!mUcvoFaFdsUsoUimU
)626ASo-+mof- )6 .+4 1(6At+4 +8o+.64 o-26A-+4 )6 23SmFUFyFUemYYmFíU
c+4 uoPf264o4 =(6 o)6+.ot+- 6. +-B.o4o4 )6 .+4 +AS+)(A+4 43-a 
U
U 8voUsFdYycdyYmFUdYamo%yimYsFíU
U "mFUcmY%mFUmcd#moUsoUivFUoySvFí 

"vFUoySvFUFvoUmYdacyimcavosFíU 

"mFUemYYmFUsFdCoUFvósdaSmFU#oacmósodsUmUsFMysYtvFUo3AS+.64 )6 2A+mmof- 3 m3SPA64of-n  
4.4  GRADO DE ISOSTATICIDAD

U noUimFUmYómSyYmFUFsUSaFdao%ysoUSvFU%YmSvFUSsUaFvFd+2omo)+)a 
U
4.4.1U YYmSvU n(dsYovíU niU cvocsudvU SsU moCiaFaFU sFU FaóaimYU m.  )6  .+  yov+L  PfA2om34  i              
UUUUUUUUUUU
IYcvFíU
4.4.2  YYmSvU)odsYovíU8sUSa aSsoUsoUSvFUumYdsFUIYómSyYmFU3imomFUgUIYómSyYmFUnFumcamisFU
lysUSsdsYóaomoUsiU%YmSvUaodsYovíU3mYmUcvóuYsoSsYUósrvYUFsU sUsoUimFU%YmMacmFU;í+U*m,U
gU*e,U
U
U
U
U U UUUUUUUUUU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
U U
U
        Figura 4.1(a)             Figura 4.1(b) 
              b barras  = 2 nnudos – 3                                     b = 3 nnudos - 6 
                              En el plano                                             En el Espacio 
  d3-)6a 
    7 a  64 6. -MS6A3 )6 7+AA+4  
    - a  6. -(S6A3 )6 -()34n
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  184  -U
U
U 8sUóvFdYmYmUsiU%YmSvUSsUaFvFdmdacaSmSUcvoUmi%yovFUYZYntFjv1 
Ejercicio #1    U
  .ósó Fó ódnósrdó sYXYdnEeód YF 5dósj sY EvjvXóXEcEsmSUaodsYovUY
)U
UUUUUUUUUUUUUUUUUUU
Solución.- 
 
  áóiYnjv orY1   e Yv YF ernYdj sY ersjv  e G D 
U UUUUUUUUUUUUUUUUUUUUUUUUUeUsFUsiUoyósYvUSsUemYYmFUUeU4U<U
  kF 5dósj sY EvjvXóXEcEsós Yv1 Y
)U4UeUIU2oUHUYUU4U<UIU2*9,UHU6U4U:U
Y
)U4U:UUsodvocsFUsFU)8>8PIP) >U
Ejercicio #2   
 
.ósó Fó ódnósrdó sYcEsEd vr 5dósj sY EvjvXóXEcEsós EodsYovUY )U
 
Solución.- 
áóiYnjv orY1 e Yv YF ernYdj sY ersjv e G - 
                              eUsFUsiUoyósYvUSsUemYYmFUeU4U++U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  185  -U
U
  kF 5dósj sY EvjXóXEcEsós Yv1 Y)U4UeUIU2oUHUYU4U++UIU2*J,UHU6U4U:U
Y
)U4U:UsodvocsFUsFU)8>8PIP) >U
 
Ejercicio #3    
.ósó Fó ódnósrdó sYcEsEd vr 5dósj sY EvjvXóXEcEsós EodsYovUY )U
 
Solución.- 
áóiYnjv orY1 e Yv YF ernYdj sY ersjv e G [ 
                              eUsFUsiUoyósYvUSsUemYYmFUeU4U9U
  kF 5dósj sY EvjXóXEcEsós Yv1 
Y
)U4UeUIU2oUHUYU4U9UIU2*;,UHU6U4U+U
GI = 1 YeXjecYv Yv káαgα84g,kCαk 8C.kαk:,8Cg.w 
Ejercicio #4  
  .ósó Fó ódnósrdóf sYcEsEd vr 5dósj sY EvjvXóXEcEsósUaodsYovUY )íU
 
Solución.- 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  186  -U
U
        áóiYnjv orY1  e Yv YF ernYdj sY ersjv e G ] 
                               eUsFUsiUoyósYvUSsUemYYmFUeU4U+6 
kF 5dósj sY EvjXóXEcEsós Yv1 Y)U4UeUIU2oUHUYU4U+6UIU2*<,UHU6U4U52U
Y
) G =T YeXjecYv Yv káα:64α6:g Cw g.k46g.g  
3I1IU1n8)8P)1U I1YI8U
U
U  ymoSvUsiU%YmSvUSsUaFvFdmdacaSmSUsFU4U:UsFdmóvFU!meimoSvUSsUyomUsFdYycdyYmUn8PIP) ITUsoU
cmFvU SsU lysU siU %YmSvU SsU aFvFdmdacaSmSU MysFsU hU +U sodvocsFU !meimóvFU SsU yomU sFdYycdyYmU
káαgα84g,kCαk 8C.kαk:,8Cg.gf u vE prYvY nYejd orY cYdj YedvocsFUFsYamUyomUsFdYycdyYmU
Cw g.k46g.g Sg:g :ká8áα8: 4g:Ygáz  
U
  αóF cjnj vY nrYvXdó Ye Fó vE5rEYeXY XóiFó1 
  Tabla 4.1 condiciones de isostaticidad 
Condiciones de 
isostaticidad: 
Tipo de estructura 
YU`U:U
nFdYycdyYmUaosFdmeisTUovUmSscymSmUumYmU
YsFaFdaYUcmY%mFU
YU4U:U nFdCdacmósodsUSsdsYóaomSmU
YUaU:U nFdCdacmósodsUaoSsdsYóaomSmU
U
4.5   DETERMINACION DE ESFUERZOS. 
 
)ó sYXYdnEeócE3e sY YvprYdajv vY dYsrcY  ó rXEFEaód YF vE5ej ML0 tódó Fó XdóccE3e  u M=0 tódó Fó 
cjntdYvE3e óF orY YvXó vjnYXEsó reó ióddó sYXYdnEeóSmTUdmiUcvóvUFsUóysFdYmUsoUimUFa%yasodsUMa%yYmíU
U
Figura 4.2 (a)             Figura 4.2 (b) 
U 3mYmU SsdsYóaomYU ivFU sFMysYtvFU soU imFU mYómSyYmFU s(avXYe  xódEjv  n2Xjsjv  YeXdY  Fjv  cróFYv 
nYecEjeódYnjv Fjv vE5rEYeXYv1 
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  187  -U
U
 4.5.1 METODO DE LOS NUDOS.- 
 
8aUyomUmYómSyYmUsFdmUsoUslyaiaeYavTUsodvocsFUcmSmUy⇒[+δβ+θ,θ+⇒,δ[θ+δβ]β+γ→](⇒+βθγ→∑+β⇒+
β′,(⇔(]∑([⋅+ [∑+ γ→⇒γ[ω+ β⇔+ γ[δ[+ δβ+ ⇔[θ+ ⇒,δ[θ+ √[⇒θ(FdsU soU FmdaFMmcsYU imFU cvoSacavosFU SsU slyaiaeYavU
∑-
(4U:UgU∑- g4:UumYmUimFUMysYtmFUsrsYcaSmFUFveYsUsiUumFmSvYUsoUcmSmUoySvUSsUimFUmYómSyYmíU
++ =⇔+∑[√βδ((β⇒γ[+θ(2,(β⇒γβ+∑[[∑√([⇒→+,⇒+γ[δ[+umYmUmomiatmYUyomUmYómSyYmUósSamodsUsiU
γ[δ[+δβ+⇔[θ+⇒,δ[θ⋅+
+ βγβ∑(⇒β+∑(β∑[+⇔→θ+∑β→√√([⇒βθ+β⇒+⇔[θ+θ[[∑γβθ+√[oFaSsYmoSvUsiUslyaiaeYavUSsUimUmYómSyYmU
sodsYmíU"ys%vUSaeyrsUsiUSam%YmómUSsUcysYuvUiaeYsUSsUyoUoySvUlysUdso%mUuvYUivUósovFUyomUMysYtmU
√[⇒[√(δ→+ ∫+ √,→⇒δ[+ ∴θ+ δ[θ+ −,β∑•→θ+ (⇒√2⇒(γ→θ⋅+ ∞(+ βFdsU oySvU sFdmU soU yovU SsU ivFU FvuvYdsFTU FsYCU
oscsFmYavUcvovcsYUimFUYsmccavosFUs(dsYomFUsoUsiUFvuvYds,íUU
+ 5θβ+β⇔+γ[δ[+δβθ√∑(γ[+→⇒γβθ+→∑→+βθγ→]⇔β√β∑+β⇔+θβ⇒daSvUSsUyomUMysYtmUSsFcvovcaSmíU"vFUsrsFU
?U gU @U SsesoU vYasodmYFsU SsU ómosYmU lysU imFU MysYtmFU soU siU Sam%YmómU SsU cysYuvU iaeYsU uysSmoU
SsFcvóuvosYFsU MCcaiósodsU soU FyFU cvóuvosodsFU ?U gU @0U iys%vU muialysU imFU SvFU scymcavosFU SsU
slyaiaeYavUSsUMysYtmFU∑U-(U4U:Ug
U∑U-@+≤+⌠⋅+β]β+⇒[γ→∑θβ+γ→](⇒+′,β+θ(+,⇒[+δβ+⇔[θ+βαβθ+βFdmUvYasodmSvU
mU ivU imY%vU SsU yomU SsU imFU MysYtmFU SsFcvovcaSmFTU imU vdYmU MysYtmU SsFcvovcaSmU uysSsU SsdsYóaomYFsU
FyómoSvU MysYtmFU mU ivU imY%vU SsiU vdYvU srsTU SsFusrsU imFU SvFU MysYtmFU SsFcvovcaSmFU gU  sYaMalysU FyFU
FsodaSvFUcvYYscdvFíU
+ {[⇒γ(⇒,+ →⇒→⇔(•→⇒δ[+ √→δ→+ ,⇒[+ δβ+ ⇔[θ+ [γ∑[θ+ ⇒,δ[θω+ βia%asoSvU oys mósodsU yovU lysU dso%mU
√,→⇒δ[+→θ+δ[θ+(⇒√2⇒(γ→θ+∫+[∑+⇔[+β⇒[θ+,⇒→+−,β∑•→+√[⇒[√(δ→⋅+βθβ+√,β⇒γ→+′,β+,⇒→+)β•+β⇒√[⇒γ∑→δ→+
yomUMysYtmUsoUyoUóasóeYvUuvYUsiUmoCiaFaFUSsiUoySvUsoUyovUSsUFyFUs(dYsóvFTUsiUYsFyidmSvUuysSsUyFmYFsU
umYmUmomiatmYUimFUMysYtmFUlysUmcd#moUsoUsiUoySvUsoUβ⇔+[γ∑[+βγ∑β[⋅+β]β+[]θβ∑)→∑θβ+δβθδβ+⇔,β2[+,⇒→+
βθγ∑(√γ→+ →δϕβ∑β⇒√(→+ →⇔+ ∑(⇒√(([+ δβ+ ⇔→+ →√√(⇒+ ∫+ δβ+⇔→+ ∑β→√√(⇒⋅+ β√,β∑δβ+ ′,β+ ,⇒+ (β]∑[+ β⇒+
√[∑βθ(⇒+β,α→+β⇔+⇒,δ[+∫+′,β+,⇒+(β]∑[+β⇒+γβ⇒θ(⇒+α→⇔→+β⇔+⇒,δ[⋅+
+ 3[θ+→θ[θ+′,β+θβ+β⇔β→⇒+θ[⇒<+
U βγβ∑(⇒→√(⇒+βθγ∴γ(√→++++++++++++++++++++++
U  micyivUSsUYsmccavosFUSsUmuvgvUUUUUUUU
U nFMysYtvFUsoUimFUemYYmFU
IuialysóvFUsFdsUuYvcsSaóasodvUumYmUivFUFa%yasodsFUsαβ∑√(√([θ<+
U
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  188  -U
U
V
M  
(+)
Ejercicio #5    
U IomiatmYUimUmYómSyYmUuimomUdauvUG>[níU
 
Solución.-
U
PASO 1) DETERMINACION ESTATICA íU
U YYmSvUs(dsYovUU Y
nU4U6UIU6UIU:U4U:U
U YYmSvUaodsYovUUUUUUUUUUUUUY
)U4UeUIU2oUHUYU4U+6UIU2*=,UHU6U4U:U
                    Y)U4U:U
U U U U U
6í7
;
!
2
UU
U U U UU UUUUUU4aU!U4U+íJ7U
 
PASO 2) CÁLCULO DE REACCIONES DE APOYO 
U
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PASO 3) ESFUERZOS EN LAS BARRAS 
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  189  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  190  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  191  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  192  -U
U
RESUMEN DE ESFUERZOS 
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4.5.2  METODO DE LAS SECCIONES. 
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→∑γβθ+ δβ]β+ γ→](⇒+ βθγ→∑+ β⇒+ β′,(⇔(]∑([ω+ β⇒+ √[⇒θβ√,socamU uysSsoU muiacmYFsU imFU dYsFU scymcavosFU SsU
slyaiaeYavUmUcymilyasYmUSsUsFmFUumYdsFUumYmUSsdsYóa⇒→∑+⇔→θ+−,β∑•→θ+β⇒+⇔[θ+(β]∑[θ+β⇒+⇔→+θβ√√(⇒+δβ⇔+
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→∑γ(√,⇔→∑ω+ δβ]β+ γ[→∑θβ+ ,⇒→+ δβ√(θ(⇒+ θ[]∑β+ √[[+ √[YdmYU vU FsisccavomYU imU mYómSyYmíU  vóvU FvivU
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  193  -U
U
Ejercicio #6   
 
βγβ∑(⇒→∑+⇔[θ+βθ−,β∑•[θ+β⇒+⇔→θ+]→∑∑→θ+]+:UgUe2+U
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PASO 3) ESFUERZOS EN LAS BARRAS 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  194  -U
U
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emYYmFUSsFcvovcaSmFíU 8sUFsumYmUimUusYc!mUcvYdmSmUgUFsUmomiatmUimUumYdsUlysUcvo so%mU*)tlyasYSmUgU
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FsoUθU4U:íJJU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  195  -U
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U 3ysFdvUlysUb = 3n – 6, sFdmFUscymcavosFUFvoUFyMacasodsFUumYmUSsdsYóaomYUdvSmFUimFUMysYtmFU
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  196  -U
U
∑βθ[⇔,√(⇒+δβ+,√ϕ→θ+β√,→√([⇒βθ+θ(,⇔γ∴⇒β→θω+⇔[θ+⇒,SvFUSsesYCoUFsisccavomYFsUcyaSmSvFmósodsUumYmU
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  197  -U
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 Ejercicio #7 
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βγβ∑(⇒→∑+θ,θ+βθ−,β∑•[θ+√[∑∑βθ[⇒δ(β⇒γβθ⋅+
 
Solución.- 
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U U U U U

                                 Universidad Mayor de San Simón                                                                   
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ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  198  -U
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4.6   UTILIZACION DE ARMADURAS. 
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5⇒→+ →∑→δ,∑→+ βθ+ ,⇒→+ √[⇒θγ∑,√√(⇒+ ∑βγ(√,⇔→δ→+ √[⇒−[∑→SmU %sosYmiósodsU uvYU dYaCo%yivFU
MvYómSvFU uvYU sisósodvFU YscdvFU gU lysU FsU ydaiatmU umYmU FvuvYdmYU cmY%mFíU "mFU mYómSyYmFU uysSsoU FsYU
uimomFU vU sFumcamisFíUU nrsóuivFU d'uacvFU SsU mYómSyYmF+ θ[⇒<+ ,β⇒γβθω+ √β∑√ϕ→θω+ γ[∑∑βθ+ δβ+ γ∑→⇒θ(θ(⇒ω+
√0,⇔→θ+δβ+βθγ→δ([θω+βγ√⋅+∆+√[⇒γ(⇒,→√(⇒+θβ+∑βθβ⇒γ→oUmi%yovFUsrsóuivFUSsUmYómSyYmFUd'uacmF
 
 
4.6.1 Tipos de armaduras o Cerchas. 
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                                 Universidad Mayor de San Simón                                                                   
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ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  199  -U
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4.6.2 ARMADURAS PARA TECHOS . 
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VPEDIGCVLJICOEST rDCLl YOLDCEJSEMNJEYCJLEP .EMEYCLDCLPCLYVEQ IGCQISIC1LSIYCECQIDO DNEQ cDjC

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
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ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  200  -U
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Figura 4.4 Cercha tipo pendolón en el plano 
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2(7(.+A64L )6 46mmof- moAm(.+A 3 m(+)A+)+ )6 +m6A3 sFdYycdyYmiTU* sYUSsdmiisUSsUyoavosFUsoUimU
Ma%yYm,íU
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Figura 4.5 Cercha espacial en la terminal de transportes de Medellín 

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ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  201  -U
U
 
Figura 4.6 Esquema de una estructura tipo tensigrity o espacial 
4.6.3  ARMADURAS PARA PUENTES. 
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Figura 4.7 Puente de cerchas vehicular, tablero inferior 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
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ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  202  -U
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Figura 4.8 estabilización lateral de las cerchas de tablero inferior 
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m3S3 +m6A3L S+)6A+ i u3ASovf-L y6A 1ov(A+ ;n<n 
 
Figura 4.9 Viga Vierendel de acero usada en puente peatonal 
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U "mFUMysYtmFUlysU mUmUFvuvYdmYUFsUsrsYcsoUFveYsUimFUyoavosFíUU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
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ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  203  -U
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4.7  PROBLEMAS RESUELTOS. 
 
Ejercicio #8   
 
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*F0P>d> d0 c>8 Drd>8C  

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
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ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  204  -U
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V
M  
(+)
 
Solución.- 
PASO 1) DETERMINACION ESTATICA 
U U U Y )U4UeUIU2UoUHUYUUU
U U U Y
)U4U2+UIU2U*+2,UHU6U4U:UU)8>8PIP) >U
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PASO 2) CÁLCULO DE REACCIONES DE APOYO 
 >D/nD )>DU
∑UGU4U:U⇒UUG
IUIU:í9U4U:U⇒U HA = 0.6 tU
∑UF
IU4U:U⇒U:í;U*;,UHU:í7U*9,UIU:í9U*6,U4U:U⇒UU VB = 0.23 tU
∑UF
EU4U:U⇒U+2U/ IUIU:í;*=,UIU:í7*9,UIU:í9*6,U4U⇒U VA = 0.67 t 
U
U  >DP1>"U ∑U/U4U:U⇒U:í9JUIU:í;UIU:í7UHU:í26U4U:U
U
PASO 3) ESFUERZOS EN LAS BARRAS 
UUUUUUUUUUUUUUUUUUUUUU U U U UU >D/nD )>DU
U
U  ymoSvUFsUSsFcvovcsUFsodaSvUSsUsFMysYtvFUmFyóaYUPY→√√(⇒⋅+
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
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ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  205  -U
U
        
  NUDO 1 (SUPUESTO)
UU U U U UUUUUUUUUUUUUUUUU NUDO 1 (REAL) 
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                                   U
 
    
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⇒Ue
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SsFcvovcaSmFíUUU
  NUDO 2 (SUPUESTO)         NUDO 2 (REAL)  
 
U
              
              
UUUUUU
U
⇒U:í+7UHUe
2U4U:U⇒Ue 2U4U5:í+7UdU
∑U/U4U:U⇒Ue
+6U4U: 
 
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
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ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  206  -U
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               NUDO 12 (SUPUESTO)            NUDO 12 (REAL) 
 
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∑U/U4U:U⇒U:í=+U*:í=6,UIUe
+;U*:í=6,U4U:U
⇒Ue
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⇒Ue
++U4U5:í=<+UdU
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        NUDO 11 (SUPUESTO)               NUDO 11 (REAL)  
 
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U
∑UGU4U:U⇒U:í=<+UHUe
+:U4U:U
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∑U/U4U:U⇒Ue
+7UHU:í;U4U:U
⇒Ue
+7U4U5:í;UdU
U
U
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  207  -U
U
 
              NUDO 7 (SUPUESTO)          NUDO 7 (REAL) 
 
UUUUUUUUUUUUUU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU U
U
8soUθU4U:í=60U vFUθU4U:í77U
∑UGU4U:U⇒Ue
9UHUeJU*:í77,U4U:U
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JU*:í=6,U4U:U
⇒Ue
JU4U5:í2=UdU
⇒Ue
9U4U:í+7;UdU
U
 
Ejercicio #9  
U
+ ∆⇒→⇔(•→∑+⇔→+→∑→δ,∑→+γ([+∆PP⋅++Fγ[δ[+δβ+⇔[θ+D,δvF,U
 
 
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  208  -U
U
Solución.-   
  PASO 1) DETERMINACION ESTATICA 
U U U Y )U4UeUIU2oUHU6U4U:UU
UU U U Y
)U4U+JUIU2*+:,UHU6U4U:UUUU)8>8PIP) IU
  PASO 2) CÁLCULO DE REACCIONES DE APOYO 
U U U ∑UGU4U:U⇒UG IUIU:í7U4U:U
UU U ∑UF
IU4U:U⇒U:í=U*;,UIU:í7U*2í7,UIU=U/EU4U:UU
UUUUUUU UUUUUU U⇒U
VB = 0.24 tU
UU U ∑UF
EU4U:U⇒U=U/ IUIU:í=U*;,UIU:í7U*2í7,U4U:U
UUUUUUUUUUUUUUUU U U⇒U
VA = 0.56 tU
+ =√,→√(⇒+δβ+√[⇒γ∑[⇔<+
∑U/U4U:U⇒U:í79UIU:í=UHU:í2;U4U:U
PASO 3) ESFUERZOS EN LAS BARRAS   
NUDO 1 (SUPUESTO)                                        NUDO 1 (REAL) 
 
U
U e
+:UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU e+:UU4U:í79UdU
U
UUUU:í7UdUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU:í7UdUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUe
+UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUe +U4U:í7:UdUUUUU
UUUUUUUUUUUUUUUUUUUUUU
UUUUUUUUUUUUUUUUUUUUUUU:í79UdUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU:í79UdU
U
U
U U U ∑UGU4U:U⇒Ue
+UHU:í7U4U:U⇒Ue +U4U5:í7UdU
U U U ∑U/U4U:U⇒Ue
+:UHU:í79U4U:U⇒Ue +:U4U5:í79UdUU
U
 
NUDO 10 (SUPUESTO)                                      NUDO 10 (REAL) 
U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUe
<U e<U4U:í;7UdU
UUUUUUUUUUUUUUUUUUUUUUUUUUU)UαUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
UUUUUUUUUUUU
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++UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUe ++U4U:íJ2UdU
UUUUUUUUUUUUU:í79UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU:í79UdU
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  209  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  211  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  212  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  213  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  214  -U
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PASO 1) DETERMINACION ESTATICA 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  215  -U
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U
PASO 2) CÁLCULO DE REACCIONES DE APOYO 
U U ∑UGU4U:U⇒UG IUIU:í2U4U:U⇒U HA = 0.2 t 
U U ∑UF IU4U:U⇒U:í;U*;,UHU:í6U*9,UIU*:í2,U+í66UIU+2U/EU4U:U
UUUUUUUUUUUUUUUUUUUUUUUUUUUU U UU∴
VB = 0.26 tU
U U ∑UF
EU4U:U⇒U+2U/ IUIU:í;U*=,UIU:í6U*9<UIU:í2U*+í66,U4U:U
UUUUUUUUUUUUUUUUUUUUUUUUUUUU U UU∴
VA = 0.44 t 
{ΤDPΤ3<+++∑U/U4U:U⇒U:í;;UIU:í;UIU:í6UHU:í29U4U:U
PASO 3) ESFUERZOS EN LAS BARRAS 
+ =⇔+γ[δ[+δβ+⇔→θ+θβ√√([⇒βθ+√[⇒θ(θγβ+β⇒+(⇒γ∑[δ,√(∑+mUimUmYómSyYmUcasYdvFUcvYdsFUUsoUiy%mYsFU
cvo soasodsFUsFdySasóvFUsiUcvYdsU8
+UlysUFsccavomUimFUemYYmFUe+:UgUe6íU
 
BARRA 10
<+∞+UmUimUSsYsc!m,U
U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUU+í66U
U Pm%UθU4UUUUUUUUUUUUUUUUUU0UUUU8soUθU4U:í77UUUU0UUU vFUθU4U:í=6U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU2U
U
U ∑UF
U;U4U:U⇒U5*:í29,U*9,UIU:í2U*+í66,UIUe+:
(UU*;,U4U:U
U U UUUUUUUUUUU∴e
+:
(U4UU5U:í;7UdU
U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUe
+:
(UUUUUUUUUUUUUUUUUUUUUU5U:í;7U
U  vFUθU4UUUUUUUUUUUUUUUUU⇒Ue
+:U4UUUUUUUUUUUUUUUUUUUU⇒UUe +:U4U5U:í77UdU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUe
+:UUUUUUUUUUUUUUUUUUUUUUUUUU:í=6U
U U U ⇒Ue
+:U4U:í77UdUUUUUUCOMPRESION 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  216  -U
U
BARRA 3<+∞+UmUimUatlyasYSm,U
U
U U U U Pm%U θU4UUUUUUUUUS+UUUUUUMU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU UUUUUUUUUU;U
U U UUUUU U U S
+U4U2í99UóU U UUUUUU
U U ∑UF
U;U4U:U⇒U:í;;U*;,UIU*:í2,U2í99UIUe6U*2í99,U4U:U
U UUUUUUUUUUUUUUUUU U U⇒Ue
6U4U:í;9UdUUUUUTRACCIONU
Ejercicio #12  UUU
+ ∞(+ θβ+ δβθβ→+ δβγβ∑(⇒→∑+ ,⇒→+ ]→∑∑→+ (⇒√⇔(⇒→δ→ω+ δβθ,FU SsiU cvYdsU FsU U SsFcvóuvosU gU FsU dvómU
[β⇒γ[θ+γ→⇔+′,β+θβ+β⇔((⇒β+,⇒→+√[[⇒β⇒γβ+Fγ[δ[+SsUimFUFsccavosF,U
U
 
 
Solución.- 
 PASO 1) DETERMINACION ESTATICA
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  217  -U
U
U Y )U4UeUIU2oUHU6U4U:UU
U Y
)U4U+7UIU2*<,UHU6U4U:UUU)8>8PIP) IU
PASO 2) CÁLCULO DE LAS REACCIONES U
U ∑UGU4U:U⇒UG
IUHUGEUIU=:U4U:U
U ∑UF
EU4U:U⇒U7UG IUHU9:U*6,UHU<U*7:,U4U:U
U UUUUUUUUUUUUUUUU⇒U
HA = -126 kU
U ∑UF
U4U:U⇒U57:U*6,UIU<U*9:,UHU+2U/IUHU7UGIU4U:U
U UUUUUUUUUUUUUUUU⇒U
VA = 110 k 
                  
⇒UHB = 206 kU
{ΤDPΤ3<+∑U/U4U:U⇒U++:UIU9:U57:U4U:U
PASO 3) ESFUERZOS EN LAS BARRAS U
 
NUDO 5 (SUPUESTO)                                          NUDO 5 (REAL)
U
U
U
UUUUUUUUUUUUUUUUUUUUUe
7UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU UUUUUUUUUUUUUUUUUUUUe7U4U:U$U
U
UUUUUUUUUUUUUUUUUUUUUUUUθUUUUUUUUUUUUUUUUUUUU
=:U$UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU =:U$U
UUUUUUUUUUUUUUUUe
;UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUe;UUUUUUUUUU
U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUU7UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU+2U
UU 8soUθU4UUUUUUUUUUUUUU4U:í6=UUU0UUU vFUθU4UUUUUUUUUUUU4U:í<2U
+6
  +6U
UU∑UGU4U:U⇒Ue
;UHU:í<2Ue7UHU=:U4U:U
UU∑U/U4U:U⇒U:í6=Ue
7U4U:U
UUUUUUUUUUUUUUU UU⇒Ue
7U4U:U$U
UU U U ⇒Ue
;U4U5U=:U$UUU >F31n8)>DU
βγβ∑(⇒→∑+]
9<+
U U U 8soU ϖU4UUUUU+2UUUUU
U4U:í<2UUUU0UUUUU vFU4U:í6=U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUU UUUUUUU UUUUUU+6U U
UU U U U?UUUUU4UUUUUUU9UUUUUUU⇒UUU?U4U2í7UUU*!auvdsoyFm,UU U
UUUUUUUUU U UUUUUUUUUUUUU7UUUUUUUUUUUUUU+2U
U U U ⇒USU4U2í7ULU8soUϖU4U2í6+UóU U
U U ∑UF
U6U4U:U⇒U5+29U*7,UHU++:U*9,UIU9:*6,UHUe9U*2í6+,U4U:UU
UUUUUUUUUUUUUUUUUUUUUUU U UUUUUUU∴U⇒Ue
9U4U9;U<;U$UUUTRACCION 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  218  -U
U
Ejercicio #13    
+ ∆∑→δ,∑→+ ⇔→⇒→+ γ([+ G[iβ+ δβ+ →⇔(→+ ,γ(⇔(•→√(⇒+ β⇒+ ⇔→+√[⇒θγ∑,√√(⇒+ δβ+ γβ√ϕ[θ+ ∞=+
FΤ∞P∆∆D+∞PDPΤ∞+{ΤP=∞⋅++
U
 
Solución.- 
 
PASO 1) DETERMINACION ESTATICA
U
U U Y
)U4UeUIU2oUHU6U4U:UU
U U Y
)U4U+6UIU2*=,UHU6U4U:UUU)8>8PIP) IU
U
PASO 2) CÁLCULO DE LAS REACCIONES U
UUUUUUUUUUUUUUUUUUUU∑UGU4U:U⇒UG
IU5U:í7U4U:U
UUU∑UF
IU4U:U⇒U+U*2,UIU:í7U*2,UHU:í=U*9,UIU=U/EU4U:UU⇒U VB = 0.725 tU
∑UF
EU4U:U⇒U=U/ EU5+U*9,UIU:í7U*2,UIU:í=U*2,U4U:U⇒U VA = 1.075 tU
{ΤDPΤ3<++
∑U/U4U:U⇒U+í:J7UIU+UIU:í=UHU:íJ27U4U:U⇒U/U
U
PASO 3) ESFUERZOS EN LAS BARRAS U
a) cvYdsU8UIU8UlysUFsccavomUmUimFUemYYmFUe=UgUe+UsoUimUumYdsUSsYsc!mU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  219  -U
U
U
∆F∆5∆+=D+=Q53EΤ+
U
nFUuvFaeisUcvoFaSsYmYU#oacmósodsUimUumYdsUFadymSmUmUimUSsYsc!mUSsiUcvYdsU8U5U8U
U U ∑UF
=U4U:U⇒Ue +U*+,UIU:í7U*+,UHU:í=U*;,UIU:íJ27U*9,U4U:U
U U UUUUUUUUUUUUUUUU⇒Ue
+U4U+í97UdUUUUUP1I  )>DU
U ∑UF
2U4U:U⇒U5Ue
(
=
U*+,UIU:í7U*2,UHU:í=U*;,UIU:íJ27U*9,U4U:U⇒Ue
(
=
U4U5U2í+7UdU
⇒UUUUUUUUUUUUUUUUUUUUUUUUUUUUe
(
=
UUUUUUUUUUUUUUUUUUU5U2í+7U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUcvFU∞U4UUUUUUUUUUUUU⇒Ue
=U4UUUUUUUUUUUUUUU4UUe
(
=
U4UU5U2í;+U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUe
=UUUUUUUUUUUUUUUUUUU:í=<2U
  [∑+⇔[+γ→⇒γ[<++++
                e=U4U2í;+UdUU >F31n8)>DU
b) cvYdsU8+U5U8+UlysUFsccavomUmUimFUemYYmFUe9Ue+2Ue6UUsoUimUumYdsUatlyasYSmU
U
∆F∆5∆+=D+=Q53EΤ++++++++++++++++++++

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  220  -U
U
U
∑UF
6U4U:U
[∑+⇔[+γ→⇒γ[<+
5Ue
(
9
U*2,UIU:í7U*2,UIU+U*2,UHU+í:J7U*;,U4U:U⇒Ue
(
9
U4U5U+í6UdU
U ⇒U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUe
(
9UUUUUUUUUUUUUU
UUUUUUUUUUUU5U+í6UUUU
UU U UcvFU ∞U4UUUUUUUUUUUUUU⇒Ue
9U4UUUUUUUUUUUUUUUUUU4U5U+í;7JUdUU U U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUe
9UUUUUUUUUUUUUUUUUUUUUUU:í=<2U
++ [∑+⇔[+γ→⇒γ[<+
e
9U4U+í;7JUdUUU >F31n8)>DU
U  voFaSsYmoSvUimUumYdsUSsUimUmYómSyYmUFadymSmUmUimUSsYsc!mUSsiUcvYdsU8
+UIU8+íU
∑UF
9U4U:U⇒Ue 6U*+,UIU:íJ27U*2,U4U:U⇒Ue 6U4U+í;7UdUUUP1I  )>DU
U  voFaSsYsóvFUSsUoys vUimUumYdsUFadymSmUmUimUatlyasYSmUSsiUcvYdsU8
+UIU8+UU
U U ⇒UU∑UF
JU4U:U⇒U5:í7U*2,UHU+í:J7U*2,UIUe6U*2,UIUe
(
+2
U*2,U4U:U
+ β∑[<+
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUe
(
+2UUUUUUUUUUUUUU
UUUUUUUUUUUU5U:í=UUUU
UU U UcvFU ∞U4UUUUUUUUUUUUUU⇒Ue
+2U4UUUUUUUUUUUUUUUUUU4U5U:í=<JUdUU U U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUe
+2UUUUUUUUUUUUUUUUUUUUUU:í=<2U
+ [∑+⇔[+γ→⇒γ[<+
U U U U e
+2U4U:í=<JUdUUU >F31n8)>DU
U
c)UcvYdsU82UIU82UlysUFsccavomUimFUemYYmFUe=TUe<TUe2TUsodvocsFUUU
U
∆F∆5∆+=D+=Q53EΤ+

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  221  -U
U
∑UF+U4U:UU∴+*2,UIUe <U*2,U4U:U⇒Ue <U4U+UdUUUP1I  )>DU
U
d) cvYdsU86UIU86UlysUFsccavomUmUimFUemYYmFUeJTUe+:UgUe2U
U
∆F∆5∆+=D+=Q53EΤ+
U U
∑UF
=U4U:U⇒U5Ue 2U*+,UHU+í:J7U*2,UIU:í7U*+,U4U:U⇒Ue 2U4U+í97UdUUP1I  )>DU
∑UF
6U4U:U⇒U5Ue
(
J
U*2,UIU:í7U*2,UHU:í=U*2,UIU:íJ27U*;,U4U:U⇒Ue
(
J
U4U5U+í+7UdU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUe
(
JUUUUUUUUUUUUUU
UUUUUUUUUUUU5U+í+7UUUU
UU U UcvFU ∞U4UUUUUUUUUUUUUU⇒Ue
JUU4UUUUUUUUUUUUUUUUUU4U5U+í2=<UdUU U U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUe
JUUUUUUUUUUUUUUUUUUUUUU:í=<2U
+ [∑+⇔[+γ→⇒γ[<+
e
JU4U+í2=<UU >F31n8)>DU
∑UF
2U4U:U⇒U5Ue
(
+:U
*+,UHU+í+7U*+,UHU+í:J7U*2,UIU:í7U*+,U4U:U⇒Ue
(
+:
U4U5U:í7UdU
U U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUe
(
+:UUUUUUUUUUUUUU
UUUUUUUUUUUU5U:í7UUUU
UU U UcvFU ∞U4UUUUUUUUUUUUUU⇒Ue
+:U4UUUUUUUUUUUUUUUUUU4U5U:í79UdUU U U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUe
+:UUUUUUUUUUUUUUUUUUUUUU:í=<2U
U
⇒e
+:U4U:í79UU >F31n8)>DU
U
e) cvYdsU8;UIU8;UlysUFsccavomUmUimFUemYYmFUe;UgUe7U
U
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  222  -U
U
U
U
U
U
∆F∆5∆+=D+=Q53EΤ+
U
U
U
∑UF
9U4U:U⇒U5Ue ;U*+,UHU:í7U*+,UHU+í:J7U*9,U4U:U⇒Ue ;U4U+í;7UdUUP1I  )>DU
∑UF
;U4U:U⇒U5Ue
(
7
U*+,UIU:í7U*2,UHU+í:J7U*9,UIU+U*;,U4U:U⇒Ue
(
7
U4U5U+í;7UdU
U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUe
(
7UUUUUUUUUUUUUUU
UUUUUUUUUUUU5U+í;7UUUU
UU U UcvFU ∞U4UUUUUUUUUUUUUU⇒UUe
7UU4UUUUUUUUUUUUUUUUUU4U5U+í927UdUU U U
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUe
7UUUUUUUUUUUUUUUUUUUUUUU:í=<2U
U
⇒UUUUUe
7U4U+í927UdUUU >F31n8)>DU
 
f) 
cvYdsU87UIU87UlysUFsccavomUmUimFUemYYmFUeJTUe++TUe+6UgUe;U
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  223  -U
U
U
∆F∆5∆+=D+=Q53EΤ+
U
∑UF
9U4U:U⇒U5Ue ++U*2,UHU:í7U*+,UHU+í+7U*+,UHU:í7J7U*2,UHU+í;7U*+,UIU:íJ27UU4U:UUUUUUUUUUUUUUUUUUU
⇒Ue
++U4U+í;7UdUUUP1I  )>DU
∑UF
JU4U:U⇒U:í=U*2,UHUe+6U*2,UIU:í;U*2,UIU:í=U*+,UHU+í;7U*2,UIU:íJ27U*;,U4U:UU
⇒Ue
+6U4U:UdU
+ ∆+√[⇒γ(⇒,→√(⇒+)β[θ+,⇒+∑βθ,β⇒+δβ+⇔[θ+βθ−,β∑•[θ+β⇒UimUemYYmFíU
U
1.075 t
0.5 t
e
U=U42í;+Ud
e
UJU4+í2=<Ud
e+U4+í97Ud e 2U4+í97Ud e 6U4+í;7Ud e ;U4+í;7Ud
0.725 t
eU<U4+í:Ud
e
U++U4+í=Ud
e
U+6U4:Ud
e
7U
4+í927Ud
e
U9U
4+í;7JUd
e
UU+2U4:í=<JUd
e
U+:U
4:í79Ud
1 t
0.5 t
0.8 t
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  224  -U
U
U niUsrsóuivUóysFdYmUimFUFa%yasodsFU sodmrmFUsoUsiUm⇒∴⇔(θ(θ+[∑+β⇔+γ[δ[+δβ+θβ√√([⇒βθ<+
U niU  mivYU SsiU sFMysYtvU SsU yomU SsdsYóaomSmU emYYmU ovU SsusoSsU soU %sosYmiU SsU vdYvFU  mivYsFU SsU
sFMysYtvFUuYs amósodsUcmicyimSvFTUsFUSscaYUyoUsYYvYUaoacamiUovUmMscdmUuvFdsYavYósodsíU
U nFUuvFaeisUSsdsYóaomYUsiUsFMysYtvUSsUyomUemYYmUFaoUoscsFaSmSUSsUYsFvi sYUdvSmUimUmYómSyYmíU
U 8aoUsóemY%vTUSsUsFdmFU sodmrmFUsFUuYsMsYaeisUydaia•→∑+θ(,⇔γ∴⇒β→β⇒γβ+β⇔+γ[δ[+δβ+⇔[θ+⇒,δ[θ+
gUSsUimFUFsccavosFíU
 
Ejercicio #14   
U 8sUuaSsUSsdsYóaomYUivFUsFMysYtvFUsoUcmSmUyomUSsUimθ+]→∑∑→θ++Fγ[δ[+Yβ⇒β∑→⇔+
 
Solución.- 
 
U "
(
e+
U4U*52UIU:,U4U520UU"
g
e+
U4U*56UIU2,U4U570UU"
t
e+
U4U*:UHU+,U4U+U
U
U "
e+U4U√U*52,
2
UHU*57,
2
UHU+
+
U4U√U6:U4U7í;=U
U
U "
?
e2
U4U20U"
@
e2
U4U:0U"
A
e2
U4U;0U"e2U4U√U2:UU4UU;í;JUU
U
U "
?
e6
U4U5+0U"
@
e6
U4U520U"
A
e6
U4U520U"e6U4U√U<U4U6U
U
∆ϕ[∑→<+
U ∑U-
?U4U-
?
e+
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U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  225  -U
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Ejercicio #15   
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  226  -U
U
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                                                                                                       C 3 = 0.74 
 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  227  -U
U
Ejercicio #16 UU
+ βγβ∑(⇒→∑+⇔[θ+βθ−,β∑•[θ+β⇒+√→δ→+,⇒→+δβ+⇔→θ+]→∑∑→θ⋅U
 
Solucion.- 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  228  -U
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4.8 PROBLEMAS  PROPUESTOS. 
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1 = 0.095 t  Comp. 
    b
2 = 3.120 t  Tracc. 
    b
3 = 0.279 t  Tracc. 
    b
4 = 2.553 t  Comp. 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  229  -U
U
 
Problema #2
UUU8sUuaSsUSsdsYóaomYUsiU mivYUSsiUsFMysYtvUsoUimFUemYYmFíU
 
Respuesta:        b1 = 6.684 t Tracc. 
    b
2 = 7.186 t CompíU
Problema #3UUU8sUuaSsUSsdsYóaomYUsiU mivYUSsiUsFMysYtvUsoUimFUemYYmFíU
U
U
UUUU
Respuesta:        b
1 = 6.111 t Tracc 
        b
2 = 6.630 t Comp. 
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U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  230  -U
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Problema #4UUU
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  Respuesta:  
                                                     b
1 = 0.167 t CompíU
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U
Respuesta: 
                                                                      b
1 = 0 t  
          b
2 = 2 t Comp. 
          b
3 = 2 t Comp. 
          b
4 = 2.066 t TraccíU
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  231  -U
U
Problema #6UUUU
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Respuesta: 
      R
1 = 1 t                 T b1 = 1.665 t Comp. 
      R
2 = 1.333 t   T b2 = T b3 = 0 
      R
3 = 0 t 
      R
4 = 2 t     T b4 = 0                
      R
5 = 4 t     T b5 = 4.47 t Comp. 
      R
6 = 6.333 t    T b6 = 6.333 t Tracc 

Problema #7UUUU
U 8sUuaSsUSsdsYóaomYUsiU mivYUSsiUsFMysYtvUsoUimFUemYYmFíU
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  232  -U
U
  Respuesta: 
                                                                          b
1 = 2.235 t Comp. 
                                                                          b
2 = 2.50 t Comp. 
                                                                          b
3 = 2.06 t Comp. 
 
4.9   EVALUACION DIAGNOSTICO DEL CAPITULO. 
 
 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  233  -U
U
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CAPITULO 5  
 
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LINEAS DE INFLUENCIA 
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5.1   OBJETIVO GENERAL. 
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5.3   PLANTEAMIENTO DEL PROBLEMA. 
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Figura  5.1 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  234  -U
U
 
 
Figura 5.2 
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noUimUMa%yYmU7í+UimUcmY%mU3U4U+UdUFsUsocysodYmUsoUió nEXós sYF cFódj sY Fó xE5ó u ó Yvó tjvEcE3e 
cvYYsFuvoSsUivFU mivYsFU/
IU4U/EU4U:í7UdUsoUimUMa%yYmU7í2UimUcmY%mU3U4U+UdUovUFsUsocysodYmUsoUimUóadmSU
sYF cFódj u ó Yvó erYxó tjvEcE3e sY Fó cód5ó cjddYvuvoSsUvdYvFU mivYsFUSsU/
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  ke YvXó vYecEFFó jivYdxócE3e ejv nrYvXdó orY YF xóivYUSsUimFUYsmccavosFUSsUmuvgvU/
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YZYntFjv sY cód5óv n3xEFYvz 
  g(jdó iEYe1 tódó YF YZYntFj EeEcEóFf EeXYdYvó cjejcYd sjv óvtYcXjv1 
5.3.1  PRIMERO:  –rY  precE3e  sYpEeY  Fó  xódEócE3e  sYF  xóFjd  sY  Fóv  dYmccavosFU cymoSvU imU
cód5ó cóniEó sY tjvEcE3ez 
5.3.2  SEGUNDO1 –rY tjvEcE3e sYiY jcrtód Fó cód5ó tódó orY Fóv dYóccavosFUdvósoU mivYsFU
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5.4   LINEAS DE INFLUENCIA.  
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  235  -U
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EU⇔+→⇔[∑+δβ+⇔→+∑β→√√(⇒+EUcymoSvU3U4U+UdUFsUsocysodYmUmU*+5(,U*ó,USsiUUU
UUUUUUUUUUUIuvgvíU
 
 
Ejercicio #1   
  
=⇒+β⇔+βαβ∑√(√([+′,β+θβ+,βθγ∑→+→+√[⇒γ(⇒,→√(⇒+θβ+,βδβ+[]θβ∑)→∑+′,β+β⇔+)→⇔[∑+δβ+⇔→+∑β→√√(⇒+
)β∑γ(√→⇔+ β⇒+ ∆+ δββ⇒δβ+ δβ+ ⇔→+ [θ(√(⇒+ ′,β+ [√,→+ ⇔→+ √→Y%mU 3U FveYsU imU  a%míU 8sU dYmdmU sodvocsFU SsU
δβγβ∑(⇒→∑+,⇒→+β√,→√(⇒+′,β+(⇒δ(′,β+⇔→+)→∑(→√(⇒+δβiU mivYUSsUimU sYdacmiUlysUcymoSvUimUcmY%mU3UlysU
dYmoFadsU*FsUUóys m,UFveYsUimU a%mUIEíU
 
Solución: 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  236  -U
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dvosimSmUFveYsUimU a%mTUsodvocsFUSsesUFsYUuvFaeisUs⇒√[⇒γ∑→∑+,⇒→+−,⇒√(⇒+′,β+∑β∑βθβ⇒γβ+→⇔+)→⇔[∑+δβ+⇔→+
∑β→√√(⇒+→∑→+δ(θγ(⇒γ→θ+[θ(√([⇒βθ+δβ+⇔→+√→∑2→⋅+
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                       Figura 5.4 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  237  -U
U
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5.5   PROCEDIMIENTO DE ANALISIS DE LAS LINEAS DE IN FLUENCIA. 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  238  -U
U
5.6   LINEA DE INFLUENCIA DE ESFUERZO CORTANTE. 
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Figura 5.5U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  239  -U
U
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Ejercicio #2 
 
βγβ∑(⇒→∑+⇔→+[θ(√(⇒+√[∑γ→⇒γβ+δβ⇔+γ∑β⇒⋅+
Solución: 
+ →∑→+δ→∑+→⇔(√→√(⇒+⇒,∑(√→+θβ→+→+≤+ω+]+≤+↑ω+√+≤++∫+,⇒+γ∑β⇒+δβ+√→∑2→θ+β⇒+⇔→+[θ(√(⇒+
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Ejercicio #3   
 
=⇔+√→(⇒+′,β+θβ+[]θβ∑)→ω+γ∑→⇒θ(γ→+[∑+⇔→+)(2→+δβ+,β⇒γβ+∆Eω+θβ+(δβ<+++
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θβ√√(⇒+∞+θβ→+β⇔+→θ+β′,βC[+δβ+⇔[θ+[θ(γ()[θ⋅+

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  240  -U
U
0.375
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P =1tP =1t
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Solución: 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  241  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  242  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  243  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  244  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  245  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  246  -U
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Solución: 
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  247  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  248  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  250  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  251  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  252  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  253  -U
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                                 Universidad Mayor de San Simón                                                                   
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                                 Universidad Mayor de San Simón                                                                   
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                                 Universidad Mayor de San Simón                                                                   
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  258  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
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                                 Universidad Mayor de San Simón                                                                   
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
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  áEXród Fó cód5ó S G 9 X  Ye YF Xdónj 4 ; .f XóF orYUF
nU4U:UU
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  271  -U
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UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUnU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU+UdíóU
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UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU3U4U+UdU
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UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU
UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU UUUUUUUUUUUUUUUUUUUUUUUUUUUU       d 
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UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU6UóUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU2UóU
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Respuesta:
 
    "mUcmY%mU3U4U+UdUUUmUUUU+UóUSsU U
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5.10   EVALUCION  DIAGNOSTICO DEL CAPITULO. 
 
 
3+A+ A6+.ot+A (-+ 6y+.(+mof- )o+v-342om3 A616A6-26 miUuYsFsodsUcmuadyivTUFsUuYvuvosUmiU
sFdySamodsUYsFuvoSsYUimFUFa%yasodsFUuYs%yodmFU
U  vóvUuimodsmY'mUyomUi'osmUSsUaoMiysocamXU
U QysUsFUyomUi'osmUSsUaoMiysocamXU
U  vóvUYscvovcsUimFUFsccavosFUcYadacmFUSsUcvYdmodsFUgUóvósodvFXU
U n(uialysU6UcmFvFUumYmUi'osmFUSsUaoMiysocamUSsUcvYdmodsFXU
U  vóvUFsUSsdsYóaomUimUi'osmUSsUaoMiysocamUSsiUóvósod3 1.6m23A 6- .+ 46mmof- 8X  
U d+A (- 656SP.3 )6 .b-6+ )6 o-1.(6-mo+ A6m2+-v(.+AX 
U
 
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  272  -U
U
 
 
 
 
 
CAPÍTULO 6 
 
CABLES 
 
6.1  OBJETIVO GENERAL. 
 
niUversda vUMyoSmósodmiUSsUsFdsUcmuadyivUsFU!mcsYUlysUsiUsFdySamodsUcvovtcmUsiUcvocsudvUSsU
cmeisFTUcymisFUFvoUFyFUyFvFUgUcymisFUFvoUimFUómosYmFUSsUmomiatmYivFUgUcmicyimYivFíU
U
6.2  OBJETIVOS ESPECIFICOS. 
e. 26ASo-+A 6426 m+Pb2(.3 6. 642()o+-26 P3)ABa 
U U1smiatmYUsiUcCicyivUSsUdsoFavosFUóC(aómFUgUó'oaómFUs(aFdsodsFUsoUsiUmoCiaFaFUSsUcmeisFíUU
U 1scvovcsYCUsiUyFvUSsiUivFUSaFdaodvFUdauvFUSsUcmeisFUs(aFdsodsFUFmeYCUmUlysUdauvUSsUsFdYycdyYmFUFvoU
muiacmeisFíU
U d626ASo-+A+ .+4 .3-vo2()64 )6 .34 m+7.64n 
U 16m3A)+A+ 7A6y6S6-26 6. mB.m(.3 -(SIAom3 *o-26vA+mof-L .bSo264L )6Aoy+mof-Cn  
U  vovcsYCUivFUsisósodvFUeCFacvFUsoUuysodsFUSsUiycsFUimY%mFUgUivFUdauvFUSsUcmeisFUlysUFsUyFmoUumYmU
sFdvFíU
6.3  INTRODUCCION. 
c+4 642A(m2(A+4 P3A 4( 13AS+ v63SI2Aom+ 6- 6. m3-26(dvUSsUFyFUsisósodvFUlysUimFUaods%YmoUFsU
cimFaMacmoUsoUYscdmFTUcyY mFUgUSsUcvodmcdv0UumYmUFy o)6-2o1om+mof- 46 o-)om+AB- 6- +.v(-+4 .+4 m+Av+4 gU
+P3i34 M-om+S6-26 P+A+ 4( o)6-2o1om+mof-L i+ =(6 P+A+ 4( )61o-omof- 46 68P3-6- 6- .+4 4ov(o6-264 
46mmo3-64 )6 I426 m+Pb2(.3n  

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  273  -U
U
"vFUcmeisFUcvoFdadygsoUmUósoySvUivFUsisósodvFUuYaocaumisFUuvYdmSvYsFUSsUcmY%mFUsoUóyc!vFU
dauvFUSsUsFdYycdyYmF0UsoUsFdsUcmuadyivU sYsóvFUmi%yovFUSsUivFUmFuscdvFUaóuvYdmodsFUYsimcavomSvFUcvoU
FyUmoCiaFaFUsFdYycdyYmiíUU
niUcmuadyivUcvóasotmUcvoUyoUmoCiaFaFU%sosYmiUSsUivFUcmeisFTUFs%yaSvUSsUyoUmoCiaFaFUSsUmlysiivFU
cmeisFUlysUFvoUFvósdaSvFUmUyomUcmY%mUcvocsodYmSmUgUmUyomUcmY%mUyoaMvYósósodsUSaFdYaeyaSmíU
.YeXdj sYF XEtj sY cóiFYv orY Y7EvXYe óeóFEaódYnjv Fjv orY njvXdónjv ó cjeXEerócE3eR Fjv 
cmeisF
 dYcXEFyeYjv Ye crujv treXjv sY EepFY7E3e vjtjdXóe cód5óv cjecYeXdósóvf Fjv cóiFYv tódói3FEcjv 
lysUFvuvYdmoUcmY%mFUYsumYdaSmFUgUivFUcmeisFUlysUFvuvYdmoUFyUusFvUuYvuavTUóaFóvFUlysUFsUSsdmiimoUsoU
Fjv vE5rEYeXYv 5dlpEcjv1 
a) 4óiFYv tódói3FEcjv orY vjtjdXóe cód5óv dYtódXEsóv 
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Figura 6.1 
b)  meisFUlysUFvuvYdmoUFyUusFvUuYvuavíU
U
Figura 6.2 
c)  4óiFYv dYcXEFyeYjv Ye crujv treXjv sY EepFY7E3e vjuvYdmoUcmY%mFUcvocsodYmSmFíU
U
Figura 6.3 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  274  -U
U
6.4  ANÁLISIS DE LOS TIPOS DE CABLES. 
6.4.1 CABLES SOMETIDOS A CARGAS UNIFORMEMENTE DISTRIBUIDA S. 
"vFUUcmeisFUuYvuvYcavomoUyoUósSavUóygUsMacmtUumYmUFvuvYdmYUsiUusFvUóysYdvUSsUimFUdYmesFUvU
cyeasYdmFUSsUuysodsFUSsUcimYvFUvUiycsFUóygU%YmoSsFTUyoUuysodsUcvi%modsUsFUyoUsrsóuivUd'uacvUsoUsiU
lysU imU cyeasYdmU sFdmU FyFusoSaSmU SsiU cmeisU yFmoSvU yomU FsYasU SsU cvi%modsFU ómFU csYcmovFU gU
yoaMvYósósodsUFsumYmSvFíU
3mYmUmomiatmYUsFdsUuYveisómUSsdsYóaomYsóvFUuYaósYvUimUMvYómUSsUyoUcmeisUFvósdaSvUmUyomU
cmY%mU sYdacmiU
ο
ωTUSaFdYaeyaSmU!vYatvodmiósodsUsoUMvYómUeaMvYósUcvóvUFsUóysFdYmUsoUimUMa%yYmU9í;U
*m,Umly'UivFUsrsFUx, yUdasosoUFyUvYa%soUsoUsiUuyodvUómFUemrvUSsiUcmeisTUSsUómosYmUlysUimUusoSasodsUsFU
csYvUsoUsFdsUuyodvíUniUSam%YmómUSsUcysYuvUiaeYsUSsUyoUuslysCvUFs%ósodvUSsUcmeisTUcvoUivo%adySUs
∆U
FsUóysFdYmUsoUimUMa%yYmU;í2U*e,íU vóvUimUMysYtmUSsUγβ⇒θ(⇒+β⇒+β⇔+√→]⇔β+√→](→+√[⇒γ(⇒,→β⇒γβ+γ→⇒γ[+β⇒+
→2⇒(γ,δ+√[[+β⇒+δ(∑β√√(⇒+→+⇔[+⇔→∑2[+δβ+⇔→+⇔[⇒2(γ,SUSsiUcmeisTUsiUcmóeavUFsUSsovdmUcvoUT∆UsoUsiU
Sam%YmómUSsUcysYuvUiaeYsTUimUcmY%mUSaFdYaeyaSmUFsUYsuYsFsodmUuvYUFyUMysYtmUYsFyidmodsU
R a%ymiUmU
ο
ωx
∆U
lysUmcd#mUmUyomUSaFdmocamUSsU
2Vx
∆USsiUuyodvU>íU
3mYmUMaosFUSsUMmcaiaSmSUSsUcCicyivUmFyóaóvFUimUFa%y(β⇒γβ+√[⇒)β⇒√(⇒+δβ+θ(2⇒[θ<+
VVVV
M  M  M  M  
(+)(+)(+)(+)
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U 1smiatmóvFUsiUmoCiaFaFUsoUsiUFa%yasodsUcmeisUgUFyUSam%YmómUSsUcysYuvUiaeYsíU
x
y
ωο
Τ +∆Τ
θ+∆θ
θ
Τ
∆s
∆x
∆y
∆x/2
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ο
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U U UUUUUU
Figura 6.4 (a)UU U U U UUUUUUUUUUUU Figura 6.4 (b)U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  275  -U
U
∆⇔(√→⇒δ[+⇔→θ+β√,→√([⇒βθ+δβ+β′,(⇔(]∑([+θβ+[]γ(β⇒β<+
∑=0:
XF U : ,cvF*,*cvF =∆+∆++− θθθ TTT U
∑=0:
YF U :,*,*,* =∆+∆++∆+−θθωθsenTTxTsen
o
U
∑ =0:
OM U :cvF,2V,** =∆+∆−∆∆ xTsenyTxx
o
θθω U
()(δ(β⇒δ[+√→δ→+,⇒→+δβ+βθγ→θ+β√,→√([⇒βθ+β⇒γ∑β+
x
∆UgUUdvómoSvUiaóadsFUcymoSvU:→∆x TUuvYU
cvoFa%yasodsU
:
→∆y 0 :→∆θ UgU :→∆T TUvedsosóvFíU
:
,cvF*
=
dx
Td θ
U U U *+,U
O
dx
Tsend
ω
θ
=
,*U U U *2,U
UUUU UU
θdmo=
dx
dy
U U U U *6,U
⇒γβ2∑→⇒δ[+⇔→+β√,→√(⇒+ω+δ[⇒δβ+P+≤+
G+β⇒+≤⌠ω+γβ⇒β[θ<+
H
FT =θcvF UU4UUUU ddsU U *;,U
U 3vYUivUdmodvUimUcvóuvosodsU!vYatvodmiUSsUimUMysYtmUsoU
cualquier puntoUmUivUimY%vUSsiUcmeisU
usYómoscsU
constante. ⇒γβ2∑→⇒δ[+⇔→+β√,→√(⇒+ω+√[⇒θ(δβ∑→⇒δ[+′,β+P+θβ⇒θ+≤+⌠+β⇒+≤⌠ω+θβ+[]γ(β⇒β<+
xTsen
O
ωθ= UU U U *7,U
()(δ(β⇒δ[+⇔→+β√,→√(⇒+ϖ+β⇒γ∑β+⇔→+β√,→√(⇒++θβ+β⇔((⇒→+P⋅+,θ→⇒δ[+⇔,β2[+⇔→+β√,→√(⇒+φω+
uvSsóvFUvedsosYUimUusoSasodsUsoUcymilyasYUuyodvUmUi[+⇔→∑2[+δβ⇔+√→]⇔βω+θβ→⋅+
H
OF
x
dx
dy
ω
θ
==dmoU UU U *9,U
+ =−β√γ,→⇒δ[+,⇒→+θβ2,⇒δ→+(⇒γβ2∑→√(⇒+√[⇒+
y =0UsoUx =0,UYsFyidmU
2
2
x
F
y
H
O
ω
= U U U U U*J,U
=θγ→++β√,→√(⇒+βθ+√[∑∑βθ[⇒δ(β⇒γβ+→+,⇒→+
parábolaTUimUcvoFdmodsU-GUuysSsUsocvodYmYFsUyFmoSvU
⇔→+√[⇒δ(√(⇒+δβ+−∑[⇒γβ∑→+
y =h UsoUUx = LíUmF'UsodvocsFUdsoSYsóvFíU
h
L
F
O
H 2
2
ω
= U U U U *=,U
+ (⇒→⇔β⇒γβ+θ,θγ(γ,∫β⇒δ[+β⇒+⇔→+β√,→√(⇒+J+γβ⇒β[θ<+
2
2
xL
h
y=
U U U U *<,U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  276  -U
U
+ β+→√,β∑δ[+√[⇒+⇔→+β√,→√(⇒+ω+⇔→+γβ⇒θ(⇒+∴(→+βoUsiUcmeisUvcyYYsUcymoSvU θUsFUóC(aóm0U
sFdvUsFUsoU
x =LUíU3vYUdmodvUSsUimFUscymcavosFU*;,UgU*7,UdsosóvFíU 22
,*LFT
OHMAXω+= U U *+:,U
+ 5θ→⇒δ[+⇔→+β√,→√(⇒+οω+[δβ[θ+γ→](⇒+β∑βθ→∑+β⇔U
MAXT+β⇒+γ∑(⇒[θ+δβ+ωvUsFdvUsFíU
2
,2V*+ hLLT
OMAX
+=ω U U *++,U
+ Dγβθβ+′,β+ϕβ[θ+δβθ∑β√(→δ[+β⇔+βθ[+∑[([+δβ⇔+√→eisTUlysUsFU
uniformeUFveYsUimU longitudU
δβ⇔+√→]⇔β+∫+⇒[+θ[]∑β+θ,+∑[∫β√√(⇒+ϕ[∑(•[⇒γ→⇔⋅+=⇒+∑smiaSmSUyoUcmeisUFvósdaSvUmUFyUusFvUuYvuavUgUiaeYsU
SsUcymilyasYUvdYmUcmY%mTUdvómYmUyomUMvYómUSsUcyY mU
catenaria⋅+∞(⇒+β]→∑2[ω+θ(+⇔→+∑→•⇒+−⇔β√ϕ→+→+√⇔→∑[+
sFUuslysCmTUlysUsFUsiUcmFvUsoUimUómgvY'mUSsUimFUmuiacmcavosFUsFdYycdyYmisFTUsFdmUcyY mUFsUmuYv(aómU
]→θγ→⇒γβ+→+,⇒→+√,∑)→+→∑→]⇔(√→ω+√[[+θβ+δβγβ∑(⇒→+mly'íU
+ =⇒+β⇔+→⇒∴⇔(θ(θ+δβ+⇔[θ+√→]⇔βθ+βθ+([∑γ→⇒γβ+γ→](⇒UcvovcsYUimUivo%adySUdvdmiUSsiUóaFóvTUumYmU
γ→⇔+β−β√γ[+θβ+∑β√,∑∑β+→+⇔→+θ(2,(β⇒γβ+β∑βθ(⇒<+







+=
l
S
dx
dy
L
:
2
+ U U U *+2,U
+ β+ ⇔[θ+ ∑βθ,⇔γ→δ[θ+ δβ+ βθγβ+ →⇒∴⇔(θ(θω+ θβ+ (⇒γβ∑−(β∑β+ ′ysU FaU yoU cmeisU
mantieneU yomU MvYómU
→∑→]⇔(√→ω+⇔→+√→∑2→+,β∑γ→+δβ+⇔→+√,](β∑γ→+δβ+,⇒+,sodsUcvi%modsUvUSsUyomUdYmesUsFdmYCUyoaMvYósósodsU
SaFdYaeyaSmUFveYsUimUivo%adySU!vYatvodmiUuYvgscdmSmUSsiUcmeisíU3vYUdmodvUFaUimUdYmesUlysUFsUóysFdYmUsoU
imUFa%yasodsUMa%yYmUsFdmUFvuvYdmSmUuvYUyomUFsYasUSsUcvi%modsFUcsYcmovFUgUyoaMvYósósodsUFsumYmSvFTUimU
cmY%mUsoUUcmSmUcvi%modsUSsesUFsYUimUóaFómUumYmU%mYm⇒γ(•→∑+′,β+β⇔+√→]⇔β+γβ⇒2→+,⇒→+−[∑→+→∑→]⇔(√→⋅+
ISsóCFUFaUFyuvosóvFUlysUimUdYmesUsFUY'%aSmUgUlysUFsU→⇒γ(β⇒β+⇔→+β⇒δ(β⇒γβ+→∑→]⇔(√→+δβ⇔+√→]⇔βω+
β⇒γ[⇒√βθ+√,→⇔′,(β∑+√→∑2→+)(⇔+
PUSsesUFsYUa%ymiósodsUcvóumYdaSmUuvYUcmSmUcvi%modsíU
U
+ 5θ→⇒δ[+βθγ→+ϕ(γβθ(θ+[δβ[θ+β−β√γ,→∑+β⇔+→⇒∴⇔(θ(θ+sFdYycdyYmiUSsUimUdYmesUvUSsUcymilyasYUvdYmU
sFdYycdyYmU lysU sFdsU iaeYsósodsU FyFusoSaSmU uvYU siU cmeisU mF'U cvóvU FsU óysFdYmU soU imU Ma%U 9í7*m,TU
sFuscamiósodsUFaUimUdYmesUsFdmUFaóuisósodsUFvuvYdmSm0UmF'UcvóvUFvuvYdmSmUuvYUsiUcmeisUsiUmoCiaFaFUFsYCU
sFdCdacmósodsUaoSsdsYóaomSvUSsUuYaósYU%YmSvTUFaoUsóeYm%vTUFaUimUdYmesUdasosUyoUumFmSvYUaodsYovUsoU
mi%#oUuyodvUaodsYósSavUmUivUimY%vUSsUFyUivo%adySTUsθγ[+δ→∑∴+,⇒→+√[⇒δ(√(⇒+δβ+[β⇒γ[+⇒,⇔[+∫+,βδβ+
sodvocsFUsMscdymYFsUyoUmoCiaFaFUsFdYycdyYmiUsFdCdacmósodsUSsdsYóaomSvUcvóvUFsUuysSsUveFsY mYUsoUimU
Ma%U9í7U*e,íU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  277  -U
U
UUUUUUUUUUU
P
trabe libremente 
suspendida
colgantes
apoyos de cables
U
Figura 6.5(a) 
UUUUUU
P
carga movil 
a lo largo de la
trabe
U
UUUU
     Figura 6.5(b)U
U  vóvUgmU!sóvFUósocavomSvUsiUyFvUSsUcmeisFUFvoUuYavdEsós Ye Fó cjevXdrccE3e sY trYeXYv 
Y7XYevjv j sY FrcYv nru 5dóesYvf ó cjeXEerócE3e njvdYmYsóvFUmi%yovFUuysodsFUSvoSsUFsUveFsY moU
ivFUSaMsYsodsFUdauvFUSsUcmeisFíU
U
Puente de San francisco, muestra cables con colgantes fijos a la trabe 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  278  -U
U
40 m
20 m
100 - x´
A
C
B
x

 
Puente de Normandia, muestra cables ajustados directamente a la trabe 
3[θ+θ(2,(β⇒γβθ+βαβ⇔[θ+(⇔,θγ∑→∑→⇒+⇒,∑(√→β⇒γβ+βθdvFUcvocsudvFíU
Ejemplo #1 
U noUimUFa%yasodsUMa%yYmUsiUcmeisUFvuvYdmUyomUdYmesU′,β+βθ→+οϖ⌠+.2V⋅+δβγβ∑(⇒β+⇔→+γβ⇒θ(⇒+β⇒+
siUcmeisUsoUivFUuyodvFU
A, B y C. IF'UóaFóvUd yCiUsFUimUMysYtmUsoUcmSmUyovUSsUivFUcvi%modsFXU
U
40 m
20 m
100 m
A
C
B
U
Solución.- siUvYa%soUSsUivFUsrsFUcvvYSsomSvFUFsUMarmUsoUsiUuyodvUETUlysUsFUsiUuyodvUómFUemrvU
SsiU cmeisU gU soU siU lysU FyU usoSasodsU sFU a%ymiU mU csYv0+ δβ+ ⇔→+ β√,→√(⇒+ J+ θ→]β[θ+ ′,β+ ⇔→+ β√,→√(⇒+
→∑→]⇔(√→+δβ⇔+√→]⇔β+βθ<+
222;27
2
V=7:
2
x
F
x
F
mkg
x
F
y
HHH
O
=== ω
U
U 8yuvoasoSvUlysUsiUuyodvU UsFdmUyeacmSvUmUyomUSaFdmocamU(kUSsU
Bω+γβ⇒β[θ<+

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  279  -U
U
2
´
;27
2: x
F
H
= U
2
´27í2+xF
H
= U
+ ββ⇔→•→[θ+γ→](⇒+→∑→+β⇔+,⇒γ[+
AUgUYssóuimtmóvFUsiU mivYUSsUFH β⇒+⇔→+β√,→√(⇒⋅+
2
´,T+::*S
;27
;: x
F
H
−−=  
2
2
´,T+::*S ´27í2+
;27
;: x
x
−−= U
:+::::´2::´
2
=−+xx 
mx;2í;+´
=    
+ =⇒γ[⇒√βθω+δβ+⇔→θ+β√,→√([⇒βθ+∫→+β⇒,⇒√(→δ→θ+γβ⇒β[θ<U
2í69;7<,;2í;+*27í2+
2
==
H
F UkgU
xx
dx
dy
:266+í:
2í69;7<
=7:
==  
noUsiUuyodvUA. 
7=í7=,;2í;++::* −=−−=x Um 
699í+,7=í7=*:266+í:dmo
7=í7=
−=−==
−=x
Adx
dy
θ U
o
A
J<í76−=θ  
U
5θ→⇒δ[+⇔→+β√,→√(⇒++γβ⇒β[θ+
t
F
T
o
A
H
A
Jí9+
,J<í76cvF*
2í69;7<
cvF
=

==
θ
U
U
noUsiUuyodvUEUdsosóvFU
x=0.U
U U U
:dmo
:
==
=x
Adx
dy
θ  ;  :=
Bθ  
     
t
F
T
B
H
B
7í69
,:cvF*
2í69;7<
cvF
===
θ
U
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  280  -U
U
noUsiUuyodvU UdsosóvF. 
;2í;+=x Um 
<97Jí:,;2í;+*:266+í:dmo
;2í;+
===
=x
Cdx
dy
θ U
o
C
:í;;=θ  
t
F
T
o
C
H
C
Jí7:
,:í;;cvF*
2í69;7<
cvF
===
θ
U
U
 vóvUimUdYmesUsFdmUFvuvYdmSmUuvYU++Ucvi%modsFTUimUMysYtmUsoUcmSmUyovUSsUsiivFUsFU
t
mmkg
FhJ9íJ
++
,+::*V=7:
== U
6.4.2 CABLES SOMETIDOS A SU PESO PROPIO 
 vóvUgmUFsU!mUósocavomSvUivFUcmeisFUuYvuvYcavomoUyoUósSavUóygUsMacmtUumYmUFvuvYdmYUsiU
usFvUóysYdvUSsUimFUdYmesFUvUcyeasYdmFUSsUuysodsFUSs+√⇔→∑[θ+[+⇔,√βθ+,∫+2∑→⇒δβθω+β∑[+γ→](⇒+√[[+
,⇒+2∑→⇒+δ(θ[θ(γ()[+δβ+,⇒(⇒+β⇒γ∑β+βθγ∑,√γ,∑→θ+→⇔βαmSmFUvUFsumYmSmFTUumYmUmomiatmYUmlysiivFUcmeisFUlysU
sFdCoUFvósdaSvFUmUFyUuYvuavUusFvUSsdsYóaomYsóvFUimUMvYómUSsiUcmeisUmUivUimY%vUSsUFyUivo%adySU
∆8íU
 vóvUgmUFsU!mUósocavomSvTUyoUcmeisUlysUFvuvYdsUFvimósodsUFyUusFvUuYvuavUdvómYmUimUMvYómU
SsUyomUcyY mU
catenaria,+√,∫→+β√,→√(⇒+√[∑∑βθ[⇒δβ+→+,⇒→+→∑∴][⇔→+√[[+θβ+[θγ∑+→⇒γβ∑([∑β⇒γβ⋅+
∆+√[⇒γ(⇒,→√(⇒+√[⇒θ(δβ∑→[θ+β⇔+√→θ[+δβ+,⇒+√→]⇔β+′,β+FvuvYdmU#oacmósodsUFyUusFvUuYvuavTU
β⇒γ[⇒√βθ+⇔→+√→∑2→+,βδβ+δ→∑θβ+√[[+,⇒→+−,⇒√(⇒+δβ+→YcvU
SíUimFUscymcavosFUSsSycaSmFUmodsYavYósodsU
FvoU miaSmFUFaUFsUmomiatmoUcvóvU
∆(U4U∆θ+β⇒γ[⇒√βθ<+
Ejemplo #2 
IomiatmYUyoUcmeisUlysUFvuvYdmU#oacmósodsUFyUusFvUuYvuavU w*F,U4U+:Uk/m 
x
y
30 m
(-15;7.5) m (15;7.5)  m
(0;0)
U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  281  -U
U
+ =⇒+βθγβ+√→θ[<+
dy
dx
ds
U
HT =ϕcvF U
()dssTsenUUU ∫
=ωϕ U U U *+6,U

= dss
Hdx
dy
UU,*
+ω U U U *+;,U
ISsóCFTU
( ) ( )
22
dxdsdy +=U
+
2
−





=
dx
ds
dx
dyU U U *+7,U
+ β+⇔→θ+β√,→√([⇒βθ++∫+ϖ+β⇒γ[⇒√βθ+
dss
Hdx
dsUUU,*
+
+
2

=−




ω U U *+9,U
U
Paso 1)  E√,→√(⇒+δβ+⇔→+√,∑)→+′,β+∑β∑βθβ⇒γ→+β⇔+√→]⇔β+
2+
+:+:
CS
H
CS
Hdx
dy
+=+=
U
 ymoSvU
:UUT:==
dx
dy
S
+[∑+⇔[+γ→⇒γ[<+
:
2=CU
5γ(⇔(•→⇒δ[+⇔→+β√,→√(⇒+↑+γβ⇒β[θ+
S
Hdx
ds
+:
+
2
=−




 U
2
2
2+::
+
S
Hdx
ds
=−




U
+
+::
2
2
2
+=





S
Hdx
dsU
+
+::
2
2
+= S
Hdx
dsU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  282  -U
U
β+⇔→+β√,→√(⇒+δ(−β∑β⇒√(→⇔+→+)→∑(→]⇔βθ+θβ→∑→]⇔βθ+θβUdasosU
dx
S
H
ds
=
++
+::
2
2
U
6
+:
io
+:
+:
+:
2
2
2
2
C
H
SS
H
H
S
ds
H
x +






















++=






+
=∫
U
vUeasoUU
6
+:
+:
C
H
S
arcsenh
H
x +





= U
 ymoSvUs = :UTUx 4U:UsodvocsFUC
3 4U:U
H
x
senh
H
S
H
S
arcsenh
H
x
+:+:+:
+:
=⇒





= U
3vYUivUdmodvU






=
H
x
senh
H
S
+:
+:
U
GmFdmUsFdmUumYdsUFsU!mUSsdsYóaomSvUS+β⇒+−,⇒√(⇒+δβ+x, sodvocsFíU
H
x
senh
H
x
senh
H
HH
S
dx
dy +:+:
+:
+:+:
=












== U
nodvocsFU
+:
:UUU0UU:
+:
cvF!
+:
;
;
H
Cyx
C
H
xH
y
−=⇒==
+





=
U
3vYUivUdmodvU
7íJUUU0UU+7
+:
+:
cvF!
+:
==
−





=
yx
H
H
xH
y
U
3vYUivUdmodvU






−





=⇒








−





= +
+7:
cvF!J7+
+7:
cvF!
+:
7íJ
H
H
H
H
U
β+δ[⇒δβ+H≤↑+→∑[(→δ→β⇒γβω+[∑+⇔[+γ→⇒γ[<+

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  283  -U
U






−





= +
+9+
+:
cvF!
+:
+9+
xy U
gUMaomiósodsU
( )[ ]+:92í:cvF!+í+9 −= xyUCatenariaU
Paso 2)+ βγβ∑(⇒→√(⇒+δβ+⇔→+γβ⇒θ(⇒+∴(→  
,:92í:*UdmoUUUU0UUUU
cvF
xsenh
dx
dyH
T ===ϕ
ϕ  
3vYUivUdmodvU
( )[ ]xsenh:92í:mYcdmo=ϕ U
nodvocsFUumYmUx=15 mU
()[ ]<6í:mYcdmosenh=ϕ U
nodvocsFU
9=6í:cvF =ϕ U
β+[δ[+′,β+⇔→+γβ⇒θ(⇒+βθ<+
íUUUJ2í267kgrT= U
Paso 3) βγβ∑(⇒→√(⇒+δβ+⇔→+⇔[⇒2(γ,δ+δβ⇔+√→]⇔β+S,U












= xsenhS
+9+
+:
+:
+9+
2  
mS UU76í6;= U
U
6.4.3 CABLES SOMETIDOS A CARGAS CONCENTRADAS 
 ymoSvUyoUcmeisUSsUusFvUSsFuYscameisUFvuvYdmU mYamFUcmY%mFUcvocsodYmSmFTUsiUcmeisUmSvudmUimU
MvYómU SsU  mYavFU Fs%ósodvFU SsU i'osmU YscdmTU cmSmU yovUSsU ivFU cymisFU sFdmU FvósdaSvU mU yomU MysYtmU
√[⇒θγ→⇒γβ+δβ+γβ⇒θ(⇒⋅+{[⇒θ(δβ∑β+[∑+βαβ⇔[ω+β⇔+√→]⇔β+′,β+θβ+,βθγ∑→+β⇒+⇔→+θ(2,(β⇒γβ+−(2,∑→<+

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  284  -U
U
D
3 KN
B
C
3 KN
L
l1
θ
l2 l3
yc yD
U
Ily'U
θTU YsuYsFsodmU siU Co%yivU SsU imU cysYSmUAB  SsiU cmeisU gULU sFU siU cimYvU SsiU cmeisíU 8aU imFU
SaFdmocamFUL
1,  L2,  y  L3 gU imFU cmY%mFUP 1  y  P2 U FsU cvovcsoTUel  problema  es  determinar  las  nueve 
incógnitas que conforman la tensión  en cada uno de los tres segmentosTUimFUcymdYvUcvóuvosodsFUSsU
∑β→√√(⇒+β⇒+AUgUBUgUimFUMisc!mFUSsUy
UgUy+soUivFUSvFUoySvFUCUgUD⋅+→∑→+⇔→+θ[⇔,√(⇒+[δβ[θ+βθ√∑(](∑+
SvFUscymcavosFUSsUslyaiaeYavUSsUMysYtmFUsoUcmSmUyovUSsUivFUuyodvFUA,B,C y DíUsFdvUSmUyoUdvdmiUSsU
ocho+β√,→√([⇒βθ+→∑→+√[⇔βγ→∑+⇔→+θ[⇔,√(⇒+βθ+∑β√(θ[+FmesYUmi%vUFveYsUimU%svósdY'mUSsiUcmeisUumYmU
vedsosYU imUnovena  ecuaciónU oscsFmYamíU 3vYU srsóuivU FaU FsU sFuscaMacmU imU ivo%adySULU dvdmiU SsiU cmeisU
uvSsóvFU yFmYU siU dsvYsómU SsU 3adC%vYmFU umYmU YsimcavomYU cmSmU yomU SsU imFU dYsFU ivo%adySsFU SsU ivFU
θβ2β⇒γ[θω+ βθ√∑(γ[θ+ β⇒+ γ∑(⇒[θ+ δβ+
θT  y TUyTUL1,  L2,  y  L3, cvoU imU ivo%adySU dvdmi  LíU
SsFmMvYdyomSmósodsTUsFdsUdauvUSsUuYveisómUovUuysSsUYsFvi sYFsUMCcaiósodsUmUómovTUFaoUsóemY%vUvdYmU
uvFaeaiaSmSU sFU sFuscaMacmYU yomU SsU imFU Misc!mFTU Sa%móvFUy
U vUyTU soU  stU SsU imU ivo%adySU SsiU cmeisíU
G→√(⇒δ[⇔[+ →θ ω+ ⇔→θ+ β√,→√([⇒βθ+ δβ+ β′,(⇔(]∑([+ θ[⇒+ β⇒dvocsFU FyMacasodsFU umYmU vedsosYU imFU MysYtmFU
SsFcvovcaSmFUgUimUMisc!mUYsFdmodsíU&omU stUvedsoaSmUimUMisc!mUsoUcmSmUuyodvUSsUcmY%mTUimUivo%adySUSsiU
cmeisUuysSsUSsdsYóaomYFsUuvYUdYa%vovósdY'míU
IiUsMscdymYUyoUmoCiaFaFUSsUslyaiaeYavUumYmUyoUuYveisómUSsUsFdsUdauvTUimFUMysYtmFUsoUsiUcmeisU
γ→](⇒+,βδβ⇒+[]γβ⇒β∑θβ+βθ√∑(](β⇒δ[+⇔→θ+β√,→√([⇒βθUSsUslyaiaeYavUumYmUsiUcmeisUsodsYvUvUcymilyasYU
[∑√(⇒+δβ+β⇔⋅+
3[θ+θ(2,(β⇒γβθ+βαβ⇔[θ+⇒[θ+(⇔,θγ∑→∑→⇒+⇒,∑(√→β⇒γsUsFdvFUcvocsudvFíU
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  285  -U
U
Ejemplo #3 
βγβ∑(⇒β+⇔→+γβ⇒θ(⇒+β⇒+√→δ→+θβ2β⇒γ[+δβ⇔+√→]⇔β+[θγ∑→δ[+→+√[⇒γ(⇒,→√(⇒+dQ,+)→⇔[∑+γ(β⇒β+
⇔→+δ(β⇒θ(⇒+h? 
1,522
3 KN
B
C

KN
2
2
h
D
 
Solución.- [∑+(⇒θβ√√(⇒+)β[θ+′,β+ϕ→∫+√,→γ∑[+∑β→√√([⇒βθ+βγβYomFUSsFcvovcaSmFTUSvFUsoU
cmSmUmuvgvUgUdYsFUdsoFavosFUSsFcvovcaSmFUsoUsiUcmeiβ⋅+=θ→θ+J+(⇒√2⇒(γ→θω+α,⇒γ[+√[⇒+⇔→+δ(θγ→⇒√(→+ϕω+
uysSsoU SsdsYóaomYFsU cvoU imFU =U scymcavosFU SsU slyaiaeYavU SaFuvoaeisFTU∑=0:
XF∑=:
YF TU
muiacmeisFUsoUivFUuyodvFUA al D. 
5⇒+∑[√βδ((β⇒γ[+→θ+δ(∑β√γ[+δβ+θ[⇔,√(⇒+βθγ∑(]→+β⇒UcvoFaSsYmYUimUusoSasodsUSmSmUSsiUcmeisU
CD0U soU imU Fa%yasodsU Ma%yYmU FsU óysFdYmU yoU Sam%YmómU SsiU cysYuvU iaeYsU SsiU cmeisU sodsYvU gU SsU m!'U
[]γβ⇒β[θ+⇔→+γβ⇒θ(⇒+β⇒+β⇔+θβ2β⇒γ[+CD+√[[+θβ+)β+→+√[⇒γ(⇒,→√(⇒<+
:=
∑ AM ⇒ :,;*=,2*6,7í7,*7V;*,2,*7V6* =−−+ mtmtmTmT
CDCD
U
U U U U tT
CD
J<í9= U U
U 3vSsóvFUmomiatmYUm!vYmUsiUslyaiaeYavUSsUivFUuyodvFU UgUEUsoUFscysocamTUcvóvU sóvFUsoUsiU
θ(2,(β⇒γβ+δ(→2∑→→+δβ+√,β∑[+⇔(]∑β<+
A
D
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C
8 KN
V
H
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  286  -U
U
U
,⇒γ[+{<+
C
KN
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y
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U

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  287  -U
U
6.5  EJERCICIOS PROPUESTOS. 
Problema #1 
  βγβ∑(⇒→∑+⇔→θ+∑β→√√([⇒βθ+δβ+→[∫[+∫+⇔→+−β√ϕ→+√[∑∑βFuvoSasodsUmUP +UgUP2U
2233
2 t
1.5 t
Va
Ha
VB
HB
y1 y2
0.5 m
A B
1 t
U
Respuesta:       
mymy
tVtH
tVtH
BB
AA
J22í:2UUUUU0UUUUU7í:+
J22í:UUUUU0UUUUU=í+:
=í+UUUUU0UUUUU=í+:
==
== ==
U
Problema #2 
  βγβ∑(⇒→∑+⇔→θ+∑β→√√([⇒βθ+β⇒+A+β√,→√(⇒+δβ⇔+√→]⇔β+∫+P max 
A
Va
Ha
VB
HB
x
y
(b;4) m
(a;4) m
B
35 m
0.2 t/m
U
Respuesta:       
tT
xy
tVtH
AA
UU;+6í=
:+6í:UUUUncymcavoUU
7í6UUUUU0UUUUU979íJ
óm(
2
=
=
==
U
Problema #3 
  βγβ∑(⇒→∑+⇔→θ+∑β→√√([⇒βθ+β⇒+B+⇔→+β√,→√(⇒+δβ⇔+√→]⇔βω+⇔[⇒2(γ,δ+δβ⇔+√→]⇔β+∫+P max, donde solo 
actúa el peso propio del cable w(s)=2: k/m
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  288  -U
U
40 m
x
y
(0;0)
(-20;6) m (20;6) m
VB
HB
U
Respuesta:       
( )[ ]
kLtT
xy
tVtH
S
BB
:9í=:;0UU;+6í=
+:2<í:cvF!2J7í6;UUUUncymcavoUU
27í;2:UUUUU0UUUUU7í9=7
óm(
==
−=
==
U
Problema #4 
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SsUimU!vYatvodmiUgUFsumYmSvFUsodYsUFaUmU+7: m⋅+βγβ∑(⇒→∑+⇔→+⇔[⇒2(γ,δ+δβ⇔+√→]⇔β+∫+⇔→+γβ⇒θ(⇒+∴aómí
U
150 m
x
y
(0;0)
U
Respuesta:        k LtT
S
<2í+760UU+:27
óm(
== U
Problema #5 
  βγβ∑(⇒→∑+⇔→+β√,→√(⇒+δβ+⇔→+√,∑)→+δβ⇔+√→]⇔β+∫+Pmax 
10 pie
5 pie
0.2 t/m
40 pie
U
Respuesta:        tTxyEcuación UU+:270:+=2í:
óm(
2
== U
 
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  289  -U
U
 
6.6   EVALUCION  DIAGNOSTICO DEL CAPITULO. 
 
 
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U QysUsFUyomUcmdsomYamXU
 
 
 
 
 
 
 
 
 
 
 
 
 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  290  -U
U
 
 
 
CAPITULO 7  
U
U
U
U
U
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TUTORIALES DE PROGRAMAS 
U
U
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7.1  OBJETIVO GENERAL. 
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  291  -U
U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  292  -U
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+a 2 i 90 i .+4 +A2om(.+mo3-64 + 6 i 7 S )6 .+ m3-)omof- o-omo+. )6 .+ yov+ 

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  293  -U
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uYaocaumiíU

                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  294  -U
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U
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Paso4)   Resultados del programa  
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  295  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  296  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  297  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  298  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  299  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  300  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  301  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  302  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  303  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  304  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  305  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  306  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  307  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  308  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  309  -U
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                                 Universidad Mayor de San Simón                                                                   
                             Facultad de Ciencias Y Tecnología                                                                   
                             Carrera de Ingeniería Civil                                                                              U
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                               Pag  -  310  -U
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ANEXOS     TEXTO ESTUDIANTE                                                     
 
 
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                                            A - 1   
CAPÍTULO 2 
 
INTRODUCCIÓN AL ANÁLISIS  
DE LAS ESTRUCTURAS 
 
ESTRUCTURAS  
Como ves, existe una gran variedad de estructuras. En ocasiones, nos encontramos con 
estructuras  que  cumplen  la  misma  función  pero  que  están  construidas  utilizando  distintos 
materiales 
 
Las  estructuras  también  pueden  diferenciarse  notablemente  por  su  forma.  
Por  ejemplo,  un  edificio  tiene  una  estructura  de  armazón,  mientras  que  un  monitor  tiene  una 
estructura de carcasa. 
Según la forma y el material con que estén construidas pueden distinguirse tres  tipos de 
estructuras: masivas, laminares o de carcasa y de armazón 
  ESTRUCTURAS MASIVAS 
Las estructuras  masivas  son  estructuras  muy  pesadas  y  macizas  formadas  por  superficies 
anchas  y  resistentes.  Para  construirlas  se  emplea  gran  cantidad  de  material.  
Los muros  gruesos  de  los  embalses  son  ejemplos  de  estructura s  masivas.  
Las bóvedas y techos de las antiguas iglesias de piedra o los enormes pilares y arcos de los 
puentes o acueductos son otros ejemplos de estructuras masivas.  
 

ANEXOS     TEXTO ESTUDIANTE                                                     
 
 
 
ADSCRIPCION DE ESTRUCTURAS “ISOSTATICAS”                                                            A - 2   
  ESTRUCTURAS LAMINARES O DE CARCASA 
Las estructuras laminares o de carcasa están constituidas por láminas resistentes que envuelven 
al objeto, formando una caja o carcasa que protege y mantiene en su posición a las piezas que lo 
componen.  
Otros ejemplos de estructuras de carcasa son las carrocerías y fuselajes de coches y aviones, y la 
mayoría de los envases como botellas de plástico o tetra briks. 
 
  ESTRUCTURAS APORTICADAS DE ARMAZÓN O ARMADURAS  
Estas  estructuras  están  formadas  por  piezas  alargadas,  como  barras,  tubos,  pilares,  vigas, 
travesaños o cables unidos entre sí para formar una especie de esqueleto o armazón. Según la 
disposición de sus elementos, las clasificamos en: trianguladas, entramadas y colgadas. 
 
o  Las estructuras trianguladas se caracterizan por la disposición de barras formando 
triángulos. Resultan muy resistentes y ligeras a la vez. 
 
o  Las estructuras entramadas están formadas por una malla de piezas verticales y 
horizontales. 

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o  Las estructuras colgadas soportan el peso de la construcción mediante cables o barras 
que van unidos a soportes muy resistentes. 
 
APOYOS 
Grados de libertad – Estabilidad 
Hemos visto que las fuerzas en un plano pueden producir traslaciones y rotaciones. La traslación 
puede expresarse por sus dos componentes, según ejes ortogonales, y la rotación alrededor de un 
eje perpendicular al plano que contiene a las fuerzas. Diremos que una estructura plana posee tres  
grados de libertad (dos de traslación y una de rotación). Es evidente que estos grados de libertad 
deben  ser  restringidos  para  evitar  toda  tendencia  al  movimiento  de  la  estructura  y  lograr  su 
equilibrio.    Esta  restricción  está  dada  por  los  apoyos,  los  que  deben  impedir  las  diversas 
posibilidades de movimiento; aparecen las reacciones en estos apoyos formando este conjunto 
(de cargas y reacciones) un sistema de fuerzas en equilibrio. 
La  función  de  estos  apoyos  es  restringir  los  grados  de  libertad  de  la  estructura,  apareciendo 
reacciones en la dirección de los movimientos impedidos. 
 a) Apoyo  de  primer  género  (MÓVIL):  impide  desplazamiento  en  la  dirección  perpendicular  al 
plano de apoyo (figura A-1). 

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b) Apoyo  de  segundo  género  o  articulación:  impide  traslaciones  en  cualquier  dirección, 
permitiendo sólo rotaciones 
 
La dirección de la reacción puede ser cualquiera pero siempre podrá ser representada por sus dos 
componentes V y H.  No es obligación descomponer la reacción de apoyo en ejes ortogonales, se 
puede descomponer en dos direcciones cualquiera. 
c) Apoyo de tercer género o empotramiento: este tipo de apoyo impide todo tipo de movimiento 
de la estructura (dos traslaciones y una rotación) (figura 2). 
 

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Observación 
Existe  también  otro  tipo  de  equilibrio  inadmisible para  las  construcciones  y  es  el  equilibrio 
indiferente. Es cuando, al actuar una pequeña fuerza, la estructura se traslada, y si deja de actuar 
la fuerza, se restablece el equilibrio, pero en otro lugar (figura MI-19). 
 
RECONOCIMIENTO DE ESTRUCTURAS Y APOYOS  
  APOYO FIJO. Se pueden identificar por la distribución mas compleja en la base. 
    
   
  EMPOTRADO.  Aquellas que carecen de grados de libertad 
   

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  ARTICULACION. Generalmente se presentan en uniones empernadas o clavadas. 
 
    
  
 
  TIRANTES. En estructuras que necesitan soporte para equilibrarlos, generalmente se 
las observa en puentes atirantados y/o puentes colgantes. 
 
 
 
  ENTRAMADOS. Se  presenta  en  construcciones  generalmente  metálicas,  en  algunos 
casos en construcciones de gran magnitud con en la que se presenta a continuación.
 

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  ARCOS. Utilizados generalmente en la construcción de puentes, pero también se las 
utiliza para del diseño de bóvedas y construcciones arqueadas como se muestra a 
continuación. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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CAPÍTULO 3 
 
ESFUERZOS INTERNOS EN 
LAS ESTRUCTURAS 
 
  Como ya tenemos conocimiento, los esfuerzos internos de una estructura bajo el efecto de 
fuerzas externas es el siguiente 
 
  Vemos  a  continuación  un  ejemplo  claro  de  los  tipos de  esfuerzos  sobre  una  pequeña 
estructura: 
 

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VIGAS 
Vistas en todo tipo de estructuras, son de forma geométrica y dependiendo de la estructura 
el tipo de material. 
 
En este grafico se muestra una viga de hormigón armado correspondiente a un puente de luz larga  
 
En este grafico se muestra una viga de acero correspondiente a una construcción metálica 
 
POTICOS 
Según el tipo de pórtico se distinguen los siguientes:   
 
En este grafico se muestra una estructura metálica aporticada 

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En este grafico se muestra una estructura aporticada de concreto armado 
 
En este grafico se muestra una estructura aporticada de concreto armado 
 

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ARCOS 
Utilizados generalmente en la construcción de puentes, pero también se las utiliza para del 
diseño de bóvedas y construcciones arqueadas como se muestra a continuación. 
 
En este grafico se muestra un puente en forma de arco para uso viacular 
 
En este grafico se muestra un puente viga con armazón metálico en forma de arco parabólico 
  A  continuación  damos  una  muestra  de  los  tipos  de  diseño  de  estructuras  arqueadas  y 
bóvedas  
 

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En este grafico se muestra una estructura aporticada de concreto armado 
 

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CAPÍTULO 4 
 
ARMADURAS O CERCHAS 
 
Como ya tenemos conocimiento, las armaduras o cerchas pueden ser identificadas de la 
siguiente manera:
 
 

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Estos tipos de armaduras pueden ser combinadas y usadas en la construcción de paneles, 
como  también  pueden  ser  usados  independientemente  para  el  uso  de  cerchas  para  techo, 
puentes, casas, etc; veamos algunas estructuras de este tipo 
 
En este grafico se muestra un panel hecho de madera, combinando distintos tipos de armadura. 
 
En este grafico se muestra un puente de armadura metálica tipo Pratt plana 
 
 
 
 
 
 

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CAPÍTULO 5 
 
LINEAS DE INFLUENCIA 
 

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CAPÍTULO 6 
 
CABLES 
  Mas comúnmente visto en puentes de luces largas, viales y peatonales, como también en 
sostenimiento de antenas metálicas. 
 
En este grafico se muestra un puente atirantado de uso peatonal. 
 
En este grafico se muestra un puente atirantado de vial. 
 
 
 

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CAPÍTULO 7 
 
TUTORIALES DE PROGRAMAS  
PARA HEWLETT PACKARD 
 
Para poder tener mayor practica con el uso de programas para la calculadora HEWLETT 
PACKARD, aconsejamos los siguientes programas para bajar, junto a su descripción: 
 
Nombre del 
programa 
Descripción 
ARMADURAS 
Permite  la  solución  de  armaduras  o  cerchas  isostáticas  e 
hiperestaticas 
ARMADURAS 
ISOSTATICAS 
Solución de armaduras por el método de nudos 
FEM 49  Permite la solución de pórticos isostáticos e hiperestaticos 
REACCIONES FR 
Programa  sencillo  para  el  calculo  de  reacciones  y  esfuerzos 
internos (esta en Francés) 
ESF 3D 
Para  el  calculo  de  esfuerzos  internos  de  pórticos  isostáticos  o 
hiperestaticos en 3D 
QUERY  Para el calculo de cortantes en vigas y pórticos 
LCASE  Para el cálculo de pórticos. 
  Todos estos programas y mas los puedes descargar de las siguientes paginas: 
C www.hpcivil.tk  
C www.HpCivil.org 
C www.elprisma.com/apuntes  
C www.foros.construaprende.com/   
C www.pachanet.com/hpcivil/  
C www.iupsmcivil.turincon.com   
 
 

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DIRECCIONES DE INTERNET 
RELACIONADOS CON INGENIERIA CIVIL 
ESTRUCTURAS ISOSTATICAS 
 
UNIVERSIDAD  Dirección de Internet  País  
Universidad mayor de San Andrés  www.umsanet.edu.bo  BOLIVIA 
Universidad de Valle  www.univalle.edu  BOLIVIA 
Universidad Católica Boliviana  www.ucbcba.edu.bo  BOLIVIA 
Universidad san Francisco Xavier  www.usfx.edu.bo  BOLIVIA 
Universidad Técnica de Oruro  www.uto.edu.bo  BOLIVIA 
Universidad Autónoma de México  www.unam.mx   MEXICO 
Harvard University  www.harvard.edu  USA 
Princeton University  www.princeton.edu/index.shtml  USA 
Yale University  www.yale.edu  USA 
Universidad de Monterrey  www.mty.itesm.mx/principal/html  MEXICO 
Universidad Nacional de Chile  www.uchile.cl  CHILE 
George Town University  www.georgetown.edu  USA 
 
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