BEHAVIOUR OF HIGH STRENGTH COLD-FORMED STEEL COLUMNS UNDER ELEVATED TEMPERATURES

A study on the behaviour of high strength cold-formed steel lipped channel columns under elevated temperatures was conducted in this paper. A finite element model of lipped channel column was developed and verified against test results. The effects of initial local and overall geometric imperfections have been taken into consideration in the analysis. Based on the high temperature material test results, a parametric study was carried out using the verified finite element model. Both uniform and non-uniform distributions of temperatures were considered. Design method for high strength cold-formed steel lipped channel columns under uniform temperatures is proposed based on the〈Technical code of cold-formed thin-wall steel structures〉. In addition, design method for high strength cold-formed steel lipped channel columns under non-uniform temperatures is also proposed based on direct strength method. Generally, it is shown that the proposed method accurately predicts the columns strengths.