Structural Engg_Lec_2_Presentation_1.ppt

knowledge of Determinate & Indeterminate Structure

1. Structure Engineering

2. Structure Engineering
Course Outline
7
th
Semester
2012-2013

3. Objectives
•This Course aims at teaching the students the concept of
analyzing indeterminate structure using classical and up
to date methods.
•It provides students with an understanding of the
methods of analyzing indeterminate structure:
–The force method of analysis
•Flexibility Method
–The Displacement method
•Stiffness Method (An Introduction to The Finite Element Method)

6. Syllabus
•Force Method of Analysis
(flexibility method of analysis )
–Beams
–Frames
–Trusses
•Stiffness Methodsof Analysis
(Displacement Method of Analysis)
–Beams
–Frames
–Trusses

7. Syllabus
•Introduction of dynamics
•Introduction to bridge
Engineering

8. Course Materials
•Lecture Notes
–Power points slides
–Handout sheets
•Text Book
–STRUCTURAL ANALYSIS II, 7th Edition
(2009) by R. C. Hibbeler
TEXTBOOK’SINTERNETSITE:
http://www.pearsonhighered.com/bookseller/product/Structural-
Analysis/9780136020608.page

9. Reference
•Any Structural Analysis Book
•Structural Analysis, by Jack McCormac, Harper
& Row Publisher, New York, 1984
•Fundamental of Structural Analysis, by H. West
and L. Geschwindner, John Wihley & Sons, Inc.,
1993.

10. Grading Policy
•Homework and Quizzes 20%
•Midterm Exam 30%
•Final Exam 50%
Exams Dates:
Midterm Exam will be announced by the department
Final Exam:

11. Introduction
•What is statically DETERMINATE structure?
–When all the forces (reactions) in a structure can be determined
from the equilibrium equations its called statically determinate
structure
–Structure having unknown forces equal to the available
equilibrium equations
No. of unknown = 2
No. of equilibrium equations = 2
2 = 2 thus statically determinate

12. Introduction
•What is statically INETERMINATED structure
–Structure having more unknown forces than available equilibrium
equations
–Additional equations needed to solve the unknown reactions
No. of unknown = 3
No. of equilibrium equations = 2
32 thus statically Indeterminate
P

13. Indeterminate Structure
Why we study indeterminate structure
–Most of the structures designed today are statically
indeterminate
–Reinforced concrete buildings are considered in most
cases as a statically indeterminate structures since
the columns & beams are poured as continuous
member through the joints & over the supports
–More stable compare to determinate structure or in
another word safer.
–In many cases more economical than determinate.
–The comparison in the next page will enlighten more

14. Contrast
Indeterminate StructureDeterminate Structure
14
Deflection
PP3
48
PL
EI 3
192
PL
EI
4
1
Stress
PP4
PL 8
PL
2
1
Considerable compared to
indeterminate structure
Generally smaller than determinate
structure
Less moment, smaller cross section
& less material needed
High moment caused thicker
member & more material needed

15. Contrast
Indeterminate StructureDeterminate Structure
Stability in case of over load
PP
Plastic HingePlastic Hinge
Support will not develop the
horizontal force & moments that
necessary to prevent total collapse
No load redistribution
When the plastic hinge formed
certain collapse for the system
Will develop horizontal force &
moment reactions that will hold
the beam
Has the tendency to redistribute
its load to its redundant supports
When the plastic hinge formed
the system would be a
determinate structure

16. Contrast
Indeterminate StructureDeterminate Structure
Temperature
PP
Differential
Displacement
PP
No effect & no stress would be
developed in the beam
No effect & no stress would be
developed
Serious effect and stress would be
developed in the beam
Serious effect and stress would be
developed

17. Flexibility method of analysis