Abstract: A three-dimensional (3D) model of composite laminate was developed, and Virtual Crack Closure Technology (VCCT) was employed to simulate the interaction of laminate debond interface. In order to approach the realistic situation, the initial geometrical imperfection was introduced before analysis. A laminate, embedded with a circle preliminary delamination, was selected as a researh object to predict the post-buckled delimination growth along predefined debond interface. Based on the simulation result from non-lineary postbuckling analysis, low-cycle fatigue simulations were then performed with Paris law as criteria, and the prediction of fatigue delamination onset and propagation was accomplished. According to the FE analysis results, it was deduced that the onset and growth of fatigue delamination were affected by the out-of-plane displacement of thicker component for preliminary debond laminate. Furthermore, compared with axis displacement applied for crack propagation, it was also shown that the axial displacement for the fatigue analysis was much bigger.

Key words: composite laminate, VCCT (Virtual Crack Closure Technology), postbuckling, delamination, low-cycle fatigue