Computational model for predicting the low-velocity impact resistance and tolerance of composite laminates

We present a numerical model for predicting the low velocity impact resistance and tolerance of multidirectional carbon fiber-reinforced composite laminates made of non-crimp fabric. A finite element model is developed wherein the heterogeneous plies are replaced by equivalent homogeneous orthotropic plies. The low-velocity impact of a carbon–epoxy laminate is investigated using an explicit finite element model. Intralaminar failure and damage is evaluated using the 3D Hashin failure criteria and a surface-based cohesive behavior is implemented to capture the delamination between the plies. Following the low velocity impact, the finite element model is subjected to axial compression to investigate the compressive residual strength after impact, which is a measure of damage tolerance. The computational model is used to investigate the impact resistance and tolerance of a 24-ply multidirectional symmetric laminate reinforced with carbon fiber non-crimp fabric. The low velocity impact response and the compressive residual strength after impact are validated with experimental data for different levels of impact energy. It is found that the computational model can predict the impact resistance and damage tolerance for impact energies up to 50 J.