A Study on Cold-Formed Steel Lipped Channel Flexural Members at Elevated Temperature Under Various Loading Scenarios.

In this study, an attempt is made to examine the effects of loading pattern on critical temperature of the cold-formed steel (CFS) members under fire. Most of the past studies on CFS flexural members at elevated temperature included either point loading or uniform moment cases, however, critical temperature established for one loading pattern may prove to be unsafe or over-conservative in other loading scenario. Finite element model is developed using commercially available program ABAQUS and is validated against experimental and numerical results available in literature. Four types of loading patterns are considered namely, 4-point loading, 3-point loading, uniformly distributed load and uniform moment. Three load ratios: 0.3, 0.5 and 0.7 are considered in this study. Results from parametric study clearly indicate there is a significant effect on the critical temperature of the CFS steel flexural members due to change in loading patterns. Other parameters affecting the critical temperature such as non-dimensional slenderness, initial applied load levels, grade and geometric properties are also discussed in detail. Based on findings of this research two proposals are suggested in order to define critical temperature of the CFS flexural members under various loading conditions. Both the proposals are found to predict the safe critical temperature of CFS flexural members with accuracy. [ABSTRACT FROM AUTHOR]