Parametric Study of Cold-Formed Lipped Channel Flexural Members Under Fire Hazard: Fid-Bau Portal

Parametric Study of Cold-Formed Lipped Channel Flexural Members Under Fire Hazard

Singh, Ravikant / Samanta, Avik

With the advancement in constructional materials and practices, cold-formed steel (CFS) has emerged as a leading material for a cost-effective and efficient alternative to their hot-rolled counterpart. CFS members are adopted widely in commercial, personal, and public spaces. Steel, in general, is considered safe at moderately elevated temperatures, but CFS members, due to their high section factors (perimeter to area ratio) are very prone to failure at elevated temperatures and may lead to catastrophic disasters in unfortunate fire events. Fire safety is a key consideration in designing and maintaining steel structures, yet there is very limited research in the field of CFS flexural members under fire. This paper reports numerical parametric study results on cold-formed lipped channel flexural members under simply supported boundary conditions. In this study, a finite element model was developed using commercially available software package ABAQUS and validated against experimental and numerical results available in the literature; then, the developed model was adopted for parametric study. Effects of loading on the CFS-lipped channel beams (LCBs) are studied considering non-uniform thermal profiles on the cross-section of members. In heat transfer analysis, ISO 834 fire-time curve was used in order to simulate the worst fire scenario. It was found that for CFS LCBs, the Eurocode 3, Part 1.2, prediction of 350˚C is highly conservative for lateral torsional buckling at higher slenderness range, whereas in case of members having lower slenderness range and undergoing distortional or local buckling sometimes found to fail below the specified temperature range of 350˚C. It was found that the slenderness plays a vital role in defining the critical temperature of a CFS flexural members.