A study on the failure mechanisms of composite laminates simultaneously impacted by two projectiles

Abstract

With most studies concentrated on the single point isolated impact events, this work mainly investigates the failure mechanisms of composite laminates simultaneously impacted by two projectiles over low energies. A 3D intralaminar damage model combining continuum damage mechanics to analyze the in-ply damage and cohesive interface elements to simulate the delamination are applied to model the damage evolution of E-glass/epoxy composites simultaneously impacted by two projectiles. The damage model is incorporated into the Abaqus/Explicit by the subroutine VUMAT. A comparison between the simulated predictions and the experimental observations of laminates impacted by one projectile is made to verify the reasonability of the damage model applied. The simulation results indicate that the delamination initiation is not largely affected by the impact energy and the number of the projectiles. As the combined effects of the two projectiles on the laminate, the intersection of matrix damage areas in plies and the connection of delamination regions at interfaces, largely decrease the overall stiffness of the laminate and result in more serious damage.