Investigation of Instability for a Sub-Framed Steel Structure at Elevated Temperatures

Experimental evidence demonstrates the complexity of beam-to-column connections at elevated temperatures and its performance has been identified in association with instability of steel members or steel-framed structures. This paper presents a research work on the inelastic behavior of a sub-framed structure at high temperatures, adopting a component-based model to represent restraints to steel members, then produced by finite element simulation, to demonstrate performance of sub-framed structures at elevated temperatures. The finite element simulation demonstrates that instability of steel members in a sub-framed structure is associated with temperature-dependent material properties (e.g. strength or deformation) of bolted connections at the ends of steel members. In addition, connection failure mechanism is very much dependent on connection components already identified, and their strength and ductility. Instability of steel members in catenary action has also been discussed for high temperatures in this paper.