A simplified prediction method for the local buckling load of cylindrical tubes

Abstract

Local buckling is as important as column buckling, substantially, when a thin-walled tube is applied to a structural part for guaranteeing safety design. This paper newly proposes an analytic model for predicting local buckling since a conventional Plantema equation is not able to predict the local buckling load, accurately, due to perfectly plastic assumption in the tube material. The proposed analytic model adopts a plastic flow of tube material to take into consideration of strain hardening, sequentially, which has been validated with experimental and numerical buckling loads when applying a thin-walled cylindrical tube. Remarkably, it shows good agreement with numerical and experimental buckling load compared with the conventional Plantema equation.