Distortional buckling strength of cold-formed steel beam under flexure

Abstract

Cold Formed Steel (CFS) sections are widely used in construction of residential and industrial buildings owing to higher strength to weight ratio. The failure modes generally observed in CFS sections are local, distortional, or lateral-torsional buckling. Though ample works have been reported in the literature, experimental work on distortional buckling is limited. In view of this, an experimental investigation on CFS lipped Channel (C) section under four-point loading has been carried out to assess the distortional buckling behaviour under monotonic loading. Seven specimens were identified based on a parametric study carried out using CUFSM so that the specimens fail due to distortional buckling/local buckling. The flexural capacities of the C-sections were predicted using various codes and compared with the respective experimental results. Also, the experimental results are compared with the modified direct strength method proposed in the literature and it is found that the predicated strengths are in close agreement with experimental ultimate loads.