Simulation of delamination propagation for stiffened composite laminated plates

Delamination initiation and propagation behavior of stiffened composite plates was analyzed using a novel propagation criterion based on mode-mixity. Moreover, the effect of ply sequence on the mechanical performance of a skin-stringer composite laminates was investigated. Mode-mixity was obtained using strain energy release rate components, which was used then to get delamination propagation length and fracture toughness for a given delamination length. The method was certified by comparing the interfacial mechanical behavior of two standard ply sequences with those used for V-22 airplane structures.