Steel column strength models

Abstract

Abstract This paper uses a simple model to unify the two traditional approaches to steel column strength based either on the buckling of straight columns with residual stresses or on the first yield of crooked columns. The inelastic buckling and post-buckling loads of elastic-plastic-strain hardening steel columns with residual stresses are determined using the tangent, reduced, and Shanley theories. These are compared with the maximum load capacities of crooked columns which fail by inelastic bending. It is concluded that the strengths of real steel columns should be analysed by considering the inelastic bending of crooked elastic-plastic-strain hardening columns with residual stresses. It is suggested that this will be most conveniently done by using a tangent modulus theory (which assumes that the loading and unloading paths coincide) to determine the maximum load capacities.