A post-buckling compressive failure analysis framework for composite stiffened panels considering intra-, inter-laminar damage and stiffener debonding

A post-buckling failure analysis framework was established to accurately and thoroughly capture the post-buckling deformation paths and failure processes as well as bearing capacities of composite stiffened panels under uniaxial compression. In this framework, the progressive damage method to thoroughly track the intraand inter-laminar damage in laminates, the cohesive zone method to accurately examine the stiffener debonding damage, and the arc-length iteration algorithm to tracking the geometrical nonlinear post-buckling path, were all introduced. Post-buckling failure processes of a blade-stiffened panel and a large-scale hat-stiffened panel under uniaxial compression were systematically investigated. Computation cases with various damage models were designed and implemented, and the effects of intra-and inter-laminar damage, stiffener debonding, and their potential interactions on the post-buckling failure process of the stiffened panel were clarified. The predicted post-buckling failure processes of both panels were highly consistent with their experimental outcomes, thus giving evidence of the effectiveness of the failure analysis framework. It follows that a comprehensive failure mode characterization including intra-and inter-laminar damage, stiffener debonding should be all considered in a failure analysis framework for accurately predicting the failure of composite stiffened panels in engineering applications.