Strength and deflection behaviour of cold-formed steel back-to-back channels

• DOI: 10.1016/j.engstruct.2018.09.064
• Publication Date: 2018-10-10T17:59:13Z
• Authors: Jun Ye; Seyed Mohammad Mo...; Iman Hajirasouliha; Paul Shepherd; Kypros Pilakoutas
• Keywords: Cold-Formed Steel; Slippage; Strain hardening exponent

Cold-formed steel (CFS) construction can lead to more efficient designs compared hot-rolled members as a consequence of its high strength, light weight, ease fabrication, and flexibility in their cross-section profiles. However, CFS are vulnerable local, distortional overall buckling modes. This paper develops numerical model investigate the flexural strength failure modes back-to-back channel beams verifies efficiency an optimisation framework previously proposed. The incorporates non-linear stress-strain behaviour enhanced corner properties obtained from coupon tests, well initial geometric imperfections measured physical specimens. To simulate bolt bearing against plate section, connector is used that takes into account both slippage deformations. developed Finite Element (FE) models verified six four-point bending tests on beams, where excellent agreement found between experimental results FE predictions. validated then assess adequacy effective width method EC3 Direct Strength Method (DSM) estimating design capacity conventional optimum beam sections. indicate DSM provide accurate predictions for lipped A comparison tested show that, change ultimate by 7%, while strain-hardening material at round corners has negligible effects. It also shown uses reduced cross-sectional property calculate deflections, which reasonably predict deflections with slight overestimation (6%) serviceability load level.