Thin‐Walled Box Columns under Arbitrary End Loads

The purpose of this study is to investigate the ultimate strength of thin‐walled welded‐steel box columns subjected to a combination of axial load, bending moment, and shear force at the ends. The moment‐curvature‐thrust relationships, incorporating the local buckling of component plates and residual stresses, are obtained first. These relationships are used to determine the envelope of equilibrium curves from which the column curves are constructed. The presence of initial column imperfection is provided in the form of constant curvature along the length. The results are presented in the form of column curves for different values of plate slenderness, column imperfection, end moment, and moment ratio. Theoretical predictions obtained using the proposed curves are compared to a limited number of test results available in the literature.