Study On Stability And Calculation Method Of Uniaxial Symmetry L-Shape Closed Section Steel Column Under Axial Load

With the increasing development of steel structure housing,Many scholars pay their attentions to studying the property of special-Shaped column. However these studies mainly focus on the open sections columns, research which relevant to the property and stability strength of closed section columns has been lagging behind.This paper launch several relative researches about the stability strength of closed L-Shape Steel Column. Basis on Umansky Torsion Theory for closed thin walled bar, The flexural torsional buckling balance equations under eccentric loading and the elastic analytical solution which under the condition of both ends hinged and fixed was deduced. By using the engineering calculation software Mathcad, An eleastic solution file was generated, which can be used to enhance the efficiency of Calculations. Eigenvalue buckling analysis for closed L-Shape Steel Column was carried out by the helping of the large finite element software ANSYS, which has strongly proof that the flexural torsional buckling balance equations and the elastic analytical solution was correct.The Geometric imperfections and the residual stress which created by the APDL language also have been introduced to the finite element model to finding their influences to the stability strength of closed L-Shape Steel Column.Through the results of36different kinds of finite element models, the impact of width thickness ratio of plate on column ultimate strength and failure modes was analysed, which obtained the plate width thickness ratio limits that can be used to neglect the influence of local buckling.