Modelling of damage in composite materials using interface elements

A simple and robust implementation of an interface element has been addressed in this paper. A new state variable is introduced to trace the extent of damage accumulated at the interface. The element not only simulate mixed mode delamination propagation in composite materials but also satisfactorily deals with mode ratio change during the debonding process. The interface model is implemented in LS-DYNA code. The model has been applied to scaled open hole tension tests. Comparison between numerical results and experiments shows good correlation.