Failure mechanisms in twill-weave laminates: FEM predictions vs. Experiments

The mechanics of woven fabric-based laminated composites is complex, but computational models can contribute to its enhanced understanding. In this work the architecture of a twill-weave graphite epoxy laminate was characterized experimentally by microscopy of polished sections. The mechanical response under tensile loading was then investigated and a microscopic assessement of the failure mechanisms was conducted. The finite element approach was used to predict stiffness and strength using a suitable representative volume element from the twill-weave laminate. The role of texture and crimp ratio on the macroscopic stiffness and strength was investigated. Progressive failure was simulated numerically and stress distributions in the model were correlated with observed damage mechanisms.