Buckling optimization and post-buckling analysis of omega sub-stiffened composite panels using different cohesive interface properties

This paper investigates the effect of a new sub-structural configuration (omega sub-stiffener) on the buckling and post-buckling performance of an existing T-stiffened composite panel design. An optimization framework is proposed to optimize the distribution of omega sub-stiffeners, the laminate stacking sequences, and the ply orientation angles of omega sub-stiffened composite panels to yield higher initial buckling performance without adding mass. Further, different stiffener-panel cohesive interface properties are considered to analyze the underlying mechanism of omega sub-stiffeners involved in the panel's post-buckling deformation paths and ultimate failure load during the compressive post-buckling process. Results show that introducing omega sub-stiffeners into the T-stiffened composite panel can result in an increased initial buckling performance (+242.63%) and causes re-establishment of the concentrated stress region, which yields different degrees of deformation and collapse in composite panels, and alters the failure behavior and further affects the initiation and propagation of various failure modes.

Automated summary

This paper investigates the effect of a new sub-structural configuration (omega sub-stiffener) on the buckling and post-buckling performance of an existing T-stiffened composite panel design. An optimization framework is proposed to optimize the distribution of omega sub-stiffeners, the laminate stacking sequences, and the ply orientation angles of omega sub-stiffened composite panels to yield higher initial buckling performance without adding mass. Results show that introducing omega sub-stiffeners into the T-stiffened composite panel can result in an increased initial buckling performance (+242.63%) and alters the failure behavior and further affects the initiation and propagation of various failure modes.