Analysis and Design Method on Local Buckling Behavior of 960 MPa High Strength Steel Columns under Axial Compression

Abstract

In order to examine the local buckling behavior of 960 MPa (yield strength standard) high strength steel (HSS) columns under axial compression, finite element models were developed by using the finite element (FE) software, ANSYS. Local buckling of four welded box section and four welded I-section columns under axial compression considering the initial geometric imperfections and welding-induced residual stresses was investigated. The FE model was then verified by comparing the ultimate bearing capacity and bearing capacity governed by local buckling of the existing test results. Using the validated FE modeling approach, parametric analyses were conducted on the local buckling behavior of 960 MPa HSS box section and I-section columns under axial compression. Moreover, the FE analysis results and the existing test results summarized in this paper were compared with the design curves in Chinese, American and European codes. It is found that the FE model established in this paper can accurately simulate the local buckling behavior of 960 MPa HSS columns under axial compression. The initial geometric imperfection and the residual stress have little influence on the ultimate stress of 960 MPa HSS columns, but exhibit a great influence on the local buckling stress. Compared with the design methods in the Chinese, American and European codes, the new design formulae proposed in this paper were recommended for the design of the local buckling stress and post-buckling ultimate stress of 960 MPa HSS columns under axial compression.

Keywords: high strength steel,  axial compression,  local buckling,  finite element method,  design