Local Buckling Behaviour and Design of Cold-Formed Steel Compression Members at Elevated Temperatures
Due to the increasing usage of cold-formed steel structures and the correspondingly increasing fatalities and losses of properties during fires, the importance of fire safety design of cold-formed steel structures has been recognised. Since most of the fire research in steel structures was limited to hot-rolled steel structures, the structural behaviour of cold-formed steel members under fire conditions is not well understood. Therefore simulated fire experiments and finite element analyses were conducted to investigate the local buckling behaviour of cold-formed steel members subject to axial compression using lipped and unlipped channel members made of both low and high strength steels. No design rules exist for cold-formed steel members at elevated temperatures and therefore the current design rules were simply modified by considering the reduced yield strength and elasticity modulus at elevated temperatures. This paper presents the details of this investigation and the results including the accuracy of modified design rules.