Strain-Rate Dependant Damage Material Model for Layered Fabric Composites with Delamination Prediction for Impact Simulations

The use of carbon fabric reinforced polymers (CFRP) in the automotive industry increased very significantly due to their high specific stiffness and strength, their great energy absorption as well as the reduced manufacturing cost. The behaviour understanding and modelling of these materials become essential for their implementation into the design loop, needed for the deployment on mass-produced vehicles. In order to ensure the protection of pedestrians and drivers/passengers in case of collision with a CFRP panel, a model dedicated to the finite element analysis (FEA) of impacts is needed. The nonlinear material behaviour which leads to differences in the impact response of composites is attributed to fibre failure, intra- and interlaminar matrix cracking, fibre-matrix debonding and strain rate sensitivity of the matrix. Additionally, the textile composite materials are capable of large shearing prior to the ultimate failure due to the sliding and reorientation of yarns. The modelling of all these phenomena is essential to describe the impact behaviour of layered fabric composites. This study is focused on the matrix damage (intralaminar and interlaminar) modelling in a finite strain framework.