Experiments and numerical predictions of cold-formed steel members with web perforations under combined compression and minor axis bending

Abstract

In this paper the buckling behaviour of cold-formed steel (CFS) members with web perforations under combined compression and minor axis bending is experimentally and numerically studied. A total of sixteen specimens with web openings were examined, and extra three specimens without perforation were also tested for comparisons. The load–displacement performances of all specimens are discussed. The specimens generally failed in the mode of distortional-global buckling interaction. Moreover, the effect of perforations on buckling behaviour of CFS members is studied. Comparisons of buckling behaviour between members with different perforation shapes, different perforation sizes, different perforation areas and various lengths are provided. The numerical models are developed and verified by the experimental data, and the comprehensive numerical analyses are conducted to further investigate the buckling behaviour of perforated members. The strengths obtained from the tests and the numerical analyses reveal that the current Direct Strength Method (DSM) curve overestimates the load-carrying capacity of perforated beam-columns experiencing distortional buckling and a modified DSM is then proposed.