Damage development in open-hole composite specimens in fatigue. Part 2: Numerical modelling

This paper follows on from the experimental investigation in Part 1 that identified the damage mechanisms and sequence in open hole tension specimens under fatigue loading. Here a finite element modelling approach is proposed for the simulation of this damage development which leads to the ability to predict overall failure. The models use a Paris-law based cohesive interface element to model delamination and matrix cracks and their interactions. When applied to the tests from Part 1 it was found that the predicted damage process had a close match to that observed experimentally. Matrix cracking at the surface ply and initiation of matrix cracks in the subsequent plies lead to delamination through thickness, and ultimately to failure at the −45/0 interface. When run at different severities the model could predict an S–N curve which had good agreement to tests.