Structural behaviour of optimised cold-formed steel beams

Abstract

Cold-formed steel (CFS) members have been significantly employed in light gauge steel buildings due to their inherent advantages. Optimising these CFS members in order to gain enhanced load bearing capacity will result in economical and efficient building solutions. This research presents the investigation on the optimisation of CFS members subjected to flexural capacity and results. The optimisation procedure was performed using Particle Swarm Optimisation (PSO) method while the section moment capacity was determined based on the effective width method adopted in EN1993-1-3 (EC3). Theoretical and manufacturing constraints were incorporated while optimising the CFS crosssections. In total, four CFS sections (Lipped Channel Beam (LCB), Optimised LCB, Folded-Flange and Super-Sigma) were considered including novel sections in the optimisation process. The section moment capacities of these sections were also obtained through non-linear Finite Element (FE) analysis and compared with the EC3 based optimised section moment capacities. Results show that compared to the commercially available LCB with the same amount of material, the novel CFS sections possess the highest section moment capacityenhancements up to 65%. In addition, the performance of these CFS sections subject to shear and web crippling actions were also investigated using nonlinear FE analysis.