Paper Title
Distortional Buckling Analysis of Back-to-Back Cold-Formed Steel Channel Beams with Web Perforations

Abstract
This paper proposed a numerical investigation on the distortional buckling behaviour of back-to-back cold-formed steel (CFS) channel beams with web perforations under pure bending. The bending tests conducted by Wang and Young were used to verify the finite element models. According to the parametric study, it was shown that the flexural capacity of the samples subject to distortional buckling decreased with the increase of hole sizes and the downward trend became sharp when the web perforations were larger. However, the effects of hole spacing and screw spacing were limited. Based on the direct strength method (DSM), new design formulae were carried out to calculate the ultimate moment of back-to-back CFS channel beams with web perforations controlled by distortional buckling. Keywords - Cold-Formed Steel, Back-to-Back, Web Perforations, Distortional Buckling, Flexural Strength