BCCM2024 - Presentation - Ranulfo (DD) reduzida.pdf

APRESENÇÃO NO BCCM 2024 - IMPROVING FRACTURE ENERGY IN MODE II OF ADHESIVE JOINTS USING DOUBLE-DOUBLE LAMINATES

1. 1
IMPROVING FRACTURE ENERGY IN MODE II
OF ADHESIVE JOINTS USING DOUBLE-DOUBLE LAMINATES
AUTHORS: R.M. Carneiro Neto, L.L. Vignoli, C.S. Moreira, N.R. Rohem, E.M. Sampaio
LAA
PRESENTER: Prof. Ranulfo Martins Carneiro Neto

2. CONTENTS

MOTIVATION

OBJECTIVES

EXPERIMENTAL WORK

RESULTS

CONCLUSIONS
2

3. MOTIVATION
3

USE OF COMPOSITE MATERIALS
Tailored properties
Improved corrosion resistance
Improved fatigue life-cycle performance
Relatively easy to manufacture complex shapes

4. MOTIVATION
4

HOW TO ENHANCE THE MECHANICAL PROPERTIES OF AN
ADHESIVE JOINT WITH COMPOSITE SUBSTRATE?
Adhesives:Adding particles and nanoparticles, spew fillets at the ends;
Substrates:
-
Using high-toughness materials on the outer surfaces of the laminates;
-
Shaping the adherends;
-
Changing the surface treatment
-
Changing the stacking sequence of the unidirectional laminaeIS IT POSSIBLE TO IMPROVE THE PROPERTIES OF AN
ADHESIVE JOINT WHILE KEEPING THE SAME MATERIALS,
SURFACE TREATMENT, ADHESIVE, ETC.,?

5. MOTIVATION
5

QUAD
Most usual stacking sequence
General form
Laminates must be symmetric
10% rule

DOUBLE DOUBLE(DD)
Lighter structure with a faster layup
General form
Homogenization capability
When tapered, heterogeneous quad property changes, while
homogenized DD remains constant (Tsai, 2021)

6. OBJECTIVES
COMPARISONBETWEEN QUADANDDD
-
MAXIMUMLOAD
-
SHEARFRACTUREENERGY
-
DISPLACEMENTFIELDS(DICANALYSIS)
6
The JournalofAdhesion
https://doi.org/10.1080/00218464.2024.2318376
ENF TEST

7. EXPERIMENTAL WORK
7
1. Three-point bending test of laminate
ObtainingE
1
andG
13
Timoshenkobeamtheory
UNIDIRECTIONAL FIBERQUADDD
Lamina 1 4567.5
Lamina 2 90-22.5
Lamina 3 -4522.5
Lamina 4 0-67.5
Lamina 5 4567.5
Lamina 6 90-22.5
Lamina 7 -4522.5
Lamina 8 0-67.5
Lamina 9 067.5
Lamina 10 -45-22.5
Lamina 11 9022.5
Lamina 12 45-67.5
Lamina 13 067.5
Lamina 14 -45-22.5
Lamina 15 9022.5
Lamina 16 45-67.5
Midplanesymmetry
toavoidwarping
The QUAD andDD
configurationshave
equivalentstiffness

8. EXPERIMENTAL WORK
8
2. ENF test
Loadx displacementcurves
CBBMmethodusedtoobtainG
IIC
R-curves
DICanalysis
Region of interest selected for digital image correlation (DIC).

9. RESULTS –THREE-POINT BENDING TEST OF LAMINATE
9
Parametric analysis to
obtain the laminates’
effective properties using
the three-point bending
test: (a) QUAD; (b) DD
(the color bars indicate
the error range and the
pink circles are the
minimal errors).

10. RESULTS –THREE-POINT BENDING TEST OF LAMINATE
10
Force-displacement
experimental curves and
analytical initial stiffness for
the three-point bending test:
(a)
QUAD with E1=15.5GPa
and G13=1.9GPa;
(b)
(b) DD with E1=14.3GPa
and G13 =2.0GPa.

11. RESULTS –ENF TESTS
11
DD 13% HIGHER THAN QUAD

12. RESULTS –ENF TESTS
12
DD 38% HIGHER THAN QUAD

13. RESULTS –DIC ANALYSIS
13

14. RESULTS –DIC ANALYSIS -VERTICAL
14

15. RESULTS –CHANGEIN MAXIMUMLOAD–THIRDSTEP
15
QUAD DD

16. CONCLUSIONS
16

Maximum load in ENF test for DD joint was 13% higher than for QUAD

G
IIC
for DD joint was 38% higher than for QUAD

DD layup may delay the crack propagation when compared to QUAD

Vertical displacement fields were higher in QUAD than in the DD layup

17. 17
CONCLUSIONS
THANK YOU
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