Experimental and finite element numerical studies on the post-buckling behavior of composite stiffened panels

Abstract

Aircraft composites structures are typically made using stiffened skin construction as it provides a minimum weight solution to many design problems. However, designers are reluctant to allow composite stiffened structures to operate in the post-buckled load regimes due to their poor inter-laminar properties. The post-buckling response of cocured composite stiffened panels is explored by experiments and numerical simulations. An integrated progressive damage finite element model is presented which captures inter and intra-laminar failures in panels. Detailed analysis of measured experimental structural responses in terms of strain, deformations, the failure mode is carried out and validated from the numerical analysis.