A numerical analysis of mixed-mode delamination in carbon¯epoxy prepregs

Several material models can be found in the literature for analysing mixed-mode free edge delamination in laminated carbon¯epoxies. Although most of the models predict the laminate behaviour rather well, they are usually not very robust in a numerical analysis. In this paper three material models are assessed. It is shown that a material model based on the formalism of orthotropic damage mechanics performs best from a computational point of view. The model can easily be implemented into a finite element code and shows a robust behaviour in numerical analyses. The delamination growth can be traced over a long range, with relatively large loading steps. The effect of some material parameter variations is studied, to obtain the sensitivity to measurement errors.