Resistance and stability of cold-formed thin-walled beams with open cross-sections subjected to bending: Experimental investigations

Thin-walled cold-formed steel members are widely used in steel construction. However, members with cross-sections that are monosymmetric about their major axis exhibit characteristics that significantly influence their structural behaviour. These open sections possess low torsional rigidity and are susceptible to local and distortional buckling, as well as lateral–torsional buckling when not laterally restrained and subjected to major-axis bending. To investigate this complex stability behaviour and further enhance the knowledge of such members, an experimental program was conducted consisting of sixteen tests, comprising both 3-point and 4-point bending tests. The study included measurements of initial geometric imperfections and coupon tests in order to characterize the actual geometric and mechanical material properties. Finally, the member design resistance is assessed in accordance with the Eurocode provisions.