Structural behaviour and design of cold-formed steel unequal-leg lipped angle columns

Investigations on buckling modes of different cold-formed steel (CFS) angle sections are reported in the literature, but unequal-leg lipped angles are studied rarely. This is the first study to use embossed steel sections for structural applications and analyse their effect on buckling deformation. In the present investigation, a total of 24 CFS unequal-leg lipped angle fixed-ended columns are tested with different slenderness ratios. The failure modes are analysed and test results are compared with the design predictions from the modified Direct Strength Method (DSM). Potential reasons for erosion in post-buckling strength are reported. The comparison of experimental and design results indicated that the modified DSM is nonconservative, thus, modifications needed for accurate predictions are suggested.