Composite Materials Research Progress

Damage Evaluation and Residual Strength Prediction of CFRP Laminates … 195
Investigating more deeply the loaded side of the low damage level laminate it was
possible to find a number of broken fibres due to local shear [29], as it is shown in the SEM
image of figure 24.
A different failure mode for the fibre is shown in the SEM image of figure 25.
3
2.5
2
1.5
1
0.5
Indentation: Maimum Load (kN)
Load (kN)
B
3
2.5
2
1.5
1
0.5
0
0 2 4 6 8 10 12 14
0
0 2 4 6 8 10 12 14
M
3
2.5
2
1.5
1
0.5
P
0
0 2 4 6 8 10 12 14
Displacement (mm)
Figure 26. Transversal load-displacement curves for the three damage levels.
3.0
2.5
2.0
1.5
1.0
0.5
Load
Energy
0.0
0.0
0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0
Indentation: Maximum displacement (mm)
30.0
25.0
20.0
15.0
10.0
5.0
Indentation: Total Strain Energy
(J)
Figure 27. Maximum displacement, maximum load and total strain energy of the transversal loading
tests.