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

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. (C) 2008 Elsevier Ltd. All rights reserved.