A simplified mesoscale model for predicting the mechanical behavior of stitched CFRP laminates

This paper presents a finite element (FE) analysis of the mechanical responses for stitched CFRP laminates under different mechanical loads. Firstly, the through-thickness stitch was simplified to z-pin like reinforcement with a uniform displacement constraint on the upper and lower surfaces of the laminate. Then, a mesoscale 3D representative volume element (RVE) of the stitched composite was proposed and modeled in the FE code ABAQUS, where the reinforcing stitch, composite layers and interfaces were built. A 3D Hashin damage model and built-in cohesive elements were respectively used to predict the mechanical failure of the stitch and the damageable behavior of cohesive interfaces. Simulation results reveal the progressive damage and rupture processes of the RVE under tensile and shear mechanical loads, and macroscopic nonlinear load-displacement responses of the mesoscale model are also captured.