Damage Evolution of Buckled Composite Stiffened-Panels Under Combined Static Shear and Compression

Modern aircraft designs use composite panels with hat-shaped stiffeners, providing exceptional strength and stiffness. A recent study has used computational methods to predict damage within these panels when subjected to combined in-plane longitudinal compressive and shear loading. As the panels reach the post-buckling regime, matrix cracking, fiber rupture, and delamination can occur, which can be critical. The Enhanced Schapery Theory captures intraply damage, and the Cohesive Zone Model models delamination damage modes. The study uses multi-hat stiffened panels made of IM7/8552 carbon-reinforced epoxy, which were initially pristine. This study offers a promising methodology to understand the interaction between damage evolution and the postbuckling response of composite hat-stiffened panels under combined shear and compression. The work highlights the postbuckling capability of these panels.