Failure model for composite materials under quasi-static crushing conditions

This paper presents a failure model to simulate the crushing mechanisms of fabric composite materials. In order to realize delamination processes and resulting lamina bending modes a multi-layered discretization is applied which is composed of shell and solid elements representing the laminate plies and the resin phase. The differentiation between the two phases enables the implementation of both in-plane failure and delamination fracture criteria and appropriate parametric degradation functions. To verify the fracture and degradation model, quasi-static tests with various compression directions have been carried out. The tests were performed using truncated conical shells of different specimen geometries fabricated with glass/epoxy prepreg. Among a qualitative comparison of the experimental and simulated failure behaviour the numerical model parameters are mainly obtained by curve fitting based on the measured load characteristics. The numerical simulations compare well with the experimental results, proving the applicability of the model for fabric composites under various loading conditions.