Investigation on the buckling and postbuckling performance of aero stiffened composite panels under axial compression

Abstract

Buckling and postbuckling performances of aero stiffened composite panels were studied in this article. The average failure load is 2.43 times larger than the average buckling load, which indicates the high postbuckling carrying capacity. The failure modes are complex, which contain the debonding of skin to stiffeners, breaking of stiffeners together with tearing and splitting of skin. A method to verify the buckling patterns of stiffened composite panels was proposed by the analysis based on strains. There are four half waves in each skin bay. However, the locations of convex and concave in each skin bay are different. The buckling patterns are local buckling of skin, which keep stable without global buckling occurring during compression. Buckling load was evaluated using the governing function and a stronger result was obtained. An engineering approach to estimate the failure load was proposed, which could predict the failure load accurately. At last, the FE analysis was conducted using nonlinear method by ABAQUS. The FE results are very consistent to the experimental ones. POLYM. COMPOS., 39:2547–2559, 2018. © 2016 Society of Plastics Engineers