Local and post-local buckling of fabricated high-strength steel and composite columns

Abstract

High-strength structural steel plates are being increasingly used as composite columns in tall buildings, bridges and large infrastructure. The presence of concrete infill in these composite sections enhances their local buckling strength, and thus very slender steel plates can be used in their fabrication. This paper presents the results of an experimental study and numerical investigation of the local buckling slenderness limits for high-strength steel plates. A set of sixteen tests were conducted on both hollow steel and steel-concrete composite sections to explore their local and post-local buckling behaviour under axial compression. A numerical model which accounts for the effects of residual stresses and initial geometric imperfections was developed to predict the local buckling and post-local buckling response of box and I-section columns. This model was verified against the test results. Yield slenderness limits obtained from numerical results were compared with existing codes of practice for both hollow steel and composite sections incorporating high-strength steel plates.