Analysis and experiment of post-buckling characteristics of stiffened panel under compress load by arc-length method

As an important component in the aircraft, stiffened panel has a strong post buckling bearing capacity after initial buckling. It is of great significance to study post-buckling characteristics of stiffened panel. Conventional analysis method is based on linear elastic theory of small displacement and small strain. Without considering the changes of structure's configuration, there is large error by conventional buckling analysis method. In this paper, arc-length method is employed in aluminum alloy stiffened panel to simulate the failure process, load transfer mechanisms and ultimate load and experimental verification is carried out. The curves of strain and stress are obtained as well as ultimate load. The results indicate that initial buckling of stiffened panel occurs on skin while stiffener is the main carrying part during post-buckling. The connection of stiffener and skin is damaged, which is consistent with the experimental results. The arc-length method can track the post-buckling equilibrium path and predict the ultimate load of stiffened panel.