Finite element models are developed by using the general-purpose finite element software,ANSYS,with accurate simulation of the residual stress and the initial geometric imperfections of the specimens,to analyze and calculate the overall buckling behaviour of 11 ultra-high strength steel welded box section columns under axial compression.

This paper deduces the accurate formulas for calculating the geometric characteristics of effective cross sections of members with welded H-shaped cross sections in gabled frames,and in order to simplify the calculation,presents the corresponding approximate calculation formulas.