Computational investigation of both intra-laminar matrix cracking and inter-laminar delamination of curved composite components with cohesive elements

Curved composite components are widely used in engineering applications, such as aircraft wing spars, and subjected to complex 3D loadings. The most critical failure mechanisms of the curved parts are intra-laminar matrix cracking and inter-laminar delamination. A computational approach has been proposed to explicitly model the intra-laminar matrix cracking and inter-laminar delamination in L-shaped cross-ply laminates with cohesive elements. Zero-thickness cohesive elements with a mixed-mode traction-separation damage law are inserted in each 90° lamina to predict matrix cracking and also inserted between neighboring plies to account for inter-laminar delamination. Two laminate stacking sequences with distinguished features of isolating different modes of failure have been investigated. The simulation results confirmed that stacking sequence [0/903/02/903/0]s trends to highlight the matrix failure mode, while the stacking sequence [03/90/03/90/0/90]s trends to highlight the delamination mode. The kinking cracking across 90° plies accompanying the delamination-dominated failure mode during the subsequent crack propagation can be also predicted. The computational results have been compared with the corresponding experimental observations reported in the literature. The good agreement with the reported experimental results verified the capability and effectiveness of computational modelling approach.