Experimental investigation of flexural and web-crippling behaviour of cold-formed steel built-up ‘I-section’ beam for elevated temperature

Abstract

Recently the worldwide industrial constructions are frequently built using light gauge materials like cold-formed steel (CFS) sections due to its lightweight and affordable design systems. One important aspect of building design and construction that must be considered is fire safety. The research involved subjecting flexural and web-crippling behaviour of CFS built-up beams to controlled hightemperature conditions, then it was cooled to room temperature by furnace cooling method. Ten back-to-back built-up CFS sections were prepared to check structural performance after exposure to elevated temperatures of 500OC, 600OC and 700OC in an electrical furnace. The finite element modelling results are validated by experimental results. The validated FE models were then employed to carry out a comprehensive parametric study to investigate the effects of different webto- thickness ratios, as well as sectional size to thickness ratio. The results demonstrated that the load carrying capacity and bending moment for flexural behaviour and web-bearing capacity for web-crippling behaviour of the CFS members can be significantly affected, up to 56.04 % and 37.26 %, with reference temperature, after exposure to elevated temperature.