Simulation of multiple delaminations in impacted cross-ply laminates using a finite element model based on cohesive interface elements

Abstract The paper investigates the capability of a finite element model based on cohesive interface elements to simulate complex three-dimensional damage patterns in composite laminates subjected to low-velocity impact. The impact response and the damage process of cross-ply laminated plates with grouped ([0 3 /90 3 ]s and [90 3 /0 3 ]s) and interspersed ([0/90] 3 s) ply stacking was simulated using a FE model developed by the authors in a previous study and the numerical results were compared to experimental observations. The model provided a correct simulation of size, shape and location of the principal fracture modes occurring in impacted [0 3 /90 3 ]s and [90 3 /0 3 ]s laminates. In [0/90] 3 s laminates, characterized by a complex spatial damage distribution, the model was able to predict the approximately circular shape of the overall projected damage area and to capture the typical shape features of individual delaminations; significant discrepancies between experiments and predictions were however observed in terms of delamination sizes at single interfaces. Further investigations are needed to clarify the main reasons of these discrepancies.