Prediction of impact-induced delamination in cross-ply composite laminates using cohesive interface elements

The paper investigates the potential of cohesive interface elements for damage prediction in laminates subjected to low-velocity impact. FE models with interface elements adopting a bilinear cohesive law were first calibrated and validated by simulation of standard fracture toughness tests and then employed to model the impact response of cross-ply graphite/epoxy laminated plates.The developed model provided a correct simulation of the impact response of laminates in a wide range of energy values and successfully predicted size, shape and location of main damage mechanisms. The results of the analyses also pointed out the importance of employing a damage criterion capable of accounting for the constraining effect of out-of-plane compression on the initiation of the decohesion phase.