Study on Section Capacity of Stainless Steel Lipped-C Beam-Columns

Abstract

This paper aims to explore the buckling behavior and the section capacity of cold-formed stainless steel lipped-C stub beam-columns under combined axial compression and uniaxial bending. A total of 24 stub columns were tested comprising two sets of sections designed to fail by distortional buckling mode and local buckling mode respectively. Two alloys, austenitic S30401 and duplex S32205, were employed in the experiments. Three loading eccentricity levels (none, small and large) were designed to produce different stress gradients within the tested sections. Refined finite element models were established with ABAQUS and validated with the detailed test results. A systematic geometric and material nonlinear analysis were then carried out covering two alloys, four plate thicknesses, four local/distortional buckling slenderness levels and five loading eccentricity levels. Lastly, based on the current Direct Strength Method (DSM) design expression, the modified expression for the section capacity prediction was proposed which suits both stainless steel columns and beam-columns of lipped-C sections.