Simulation of delamination growth in multidirectional laminates under mode I and mixed mode I/II loadings using cohesive elements

A numerical model for accurately predicting the delamination propagation in multidirectional laminates under mode I and mixed-mode I/II loadings using the cohesive element is proposed in this paper. Instead of a constant fracture toughness, a fracture toughness function which reflects the variation of fiber bridging tractions, accompanying with a group of appropriate interface stiffness, interface strength, the number of cohesive elements in cohesive zone and viscosity coefficient determined by the trial and error method among recommended guidelines or values in literatures, can provide accurate simulations on the delamination growth in the multidirectional laminates. The predicted delamination behaviors of the multidirectional laminates with interfaces 0°/5°, 45°/-45° and 90°/90° in both the DCB and MMB tests are consistent with experimental outcomes, which give evidence of the effectiveness of the proposed model.