Global and local instability of thin-walled columns beyond the proportional limit

Abstract

The problem of global and local stability in the inelastic range for thin-walled columns is examined on the basis of the defonnation theory and the incremental theory of plasticity. Columns of closed and open cross-sections built from rectangular isotropic plates are subjected to the loading changing from unifonn compression to pure bending. A solution of elastic buckling for a thin-walled orthotropic columns based on Koiter's asymptotic method is employed to investigate the elasto-plastic buckling mode of the colunm and to detennine the critical load. The study is based on the numerical method of the transition matrix. The results of numerical calculations are presented in diagrams