Numerical Studies on Buckling and Post-Buckling Behavior of Stiffened Curved Composite Panel with Repairs

Composite stiffened panels are widely employed in the aircraft industry. In particular, curved panels stiffened with hat-stringers are utilized in fuselages. The panels comprise of very thin skin to which stringers are attached (cocured/ co-bonded or secondary bonded). The panels are prone to buckling phenomenon when subjected to compression, and other complex loading scenarios. The stiffened panels may be subjected damages induced by low velocity impacts, such as tool-drop. Such a scenario may yield to local reduction in the stiffness, and especially affect post-buckling response of the structure. The primary goal of this research is to develop numerical tools to study buckling and post-buckling response of stiffened composites panels containing repair. Two types of repair are considered: secondary bonded and co-bonded. It is shown that, both repair types are able to restore the panel strength, and influence the post-buckling behavior. The presented finite-element based numerical models of the repair panels are able to capture pre- and post-buckling response. The presented tool is encapsulated as a Abaqus plug-in. The presented methodology paves way