Column behaviour of cold-formed hollow structural steel shapes

Abstract

This paper presents a theoretical model describing the column behaviour of cold-formed heat-treated and non-heat-treated hollow structural steel (HSS) shapes. Member cross-sectional parameters in the form of residual stress and yield strength gradients as well as the member initial crookedness are incorporated into the column model. The parameter magnitudes used and their dispositions throughout the model are based on current experimental and theoretical research. The effect and relative importance of these parameters in determining the theoretical column strength is illustrated. The adequacy of the theoretical model in determining HSS column strength is shown by comparing it with the results of experimental tests conducted on full-sized HSS specimens. Finally, design curves for each of the HSS types studied are recommended.