Numerical study on restrained thermal elongation of cold-formed steel Column subjected to non-uniform thermal loading under transient state

Abstract

Cold-formed steel (CFS) is extensively used as non-load bearing and load-bearing structural members because of its less weight to strength ratio, transportation economy, and handling ease. Since CFS members are treated as slender sections, they are highly susceptible to buckling under the compression loads at ambient and elevated temperatures. The codes IS801, EN1993–1.3, AS/NZS4600, and BS5950 are used to design the cold-formed steel compression members at ambient temperature, and the code EN1993–1.2 is used to design the CFS member by treating it as a slender member with a limiting temperature of 350 °C. Many researchers have attempted to study the behaviour of CFS members at elevated temperatures, both numerically and experimentally, under uniform thermal loading conditions at steady-state. However, studies on non-uniform thermal loading under transient states are minimal. The present study focuses on the numerical modelling of buckling behaviour of CFS members with restrained thermal elongation under non-uniform temperature conditions. The numerical modelling of the CFS column subjected to non-uniform temperature under a transient state is validated with the past results. The parametric study is carried out by varying the initial load, the member's slenderness ratio, the stiffness of the supporting structure, the width-thickness ratio(w/t), and the temperature difference between flanges.