Study on Buckling of Two Kinds of Thin-walled steel Members with Imperfection

摘要

Based on Jezek method of computing the elastic-plastic buckling of the members under the axial compressive load and the bending moment, considering the initial imperfection, the analytical expressions of calculating the ultimate load of buckling about the neutral axis with the maximum moment of inertia for an H-shaped member and a square steel tube member are derived. Using the elastic-plastic finite element method and the theory of nonlinear buckling, the impact by initial geometric imperfections on the H-shaped steel member and the square steel tube member under the axial compressive load and the bending moment are analyzed and the numerical solutions of ultimate bearing capacity are obtained. By compared with the values of the finite element method (FEM), it shows that the analytical method in this paper is valid. The results of the example show that the presence of initial imperfections reduces the ultimate bearing capacity of the two kinds of steel members to a great extent. It is also found that the influence of the initial geometric imperfection on the ultimate bearing capacity of members is smaller when the bending moment increases.