Abstract: To study the buckling and post-buckling behaviors of 2A97 Al-Li alloy stiffened panels under shear loads, 2A97 Al-Li alloy stiffened panels are designed and shear static tests are performed, obtaining the buckling load, failure load and failure mode of the panels. Buckling and tension field theories are adopted to calculate the buckling behavior of the stiffened panels under shear loading and the finite element method used to model and analyze buckling behavior of the stiffened panels, the numerical results of which are compared with the experimental results. It is shown that the buckling mode of the stiffened panels is the local buckling of the skin between the ribs; the failure mode is the bulge of the skin along the loading diagonal direction, which is caused by the plastic deformation and the tear of the skin and the torsion of ribs. A relatively accurate buckling load can be obtained by the tension field theory, with an error of 6.56% compared with the experimental results. While the buckling and the failure modes are consistent with those in the experiments, the buckling load and the ultimate load have errors of 1.22% and 11.52%, respectively.

Key words: stiffened panels, shear loading, buckling and post-buckling, shear tests, finite element method