Strength of Thin‐Walled Square Steel Box Columns

Abstract

The present study is concerned with the strength of thin‐walled steel box columns of square cross section that are pinned and subjected to axial load and equal moment at the ends. The local buckling in the component plates is allowed for by using piecewise linear stress‐strain curves that are approximations of previous research findings. Due allowance is made to account for the effect of residual stresses due to welding and overall column imperfections upon the ultimate strength. The column analysis is carried out by integrating numerically along the length the moment‐curvature‐thrust relationships. This method of column analysis is free from iteration and could predict the ultimate strength accurately. The results are presented in the form of column curves and interaction diagrams for typical values of plate slenderness ratios, residual stress levels, and initial column imperfections. Comparisons are made between the proposed column curves and multiple column curves of ECCS and SSRC.