Investigation on Non-linear Interaction Framework for Zee-Shaped Cold-Formed Steel Beam-Column

This chapter deals with the ultimate strength and buckling behaviour of cold-formed steel Zee-shaped section under combined axial and bending actions. The numerical model was developed using finite element software ABAQUS. The specimen dimensions are chosen based on the elastic buckling curve from the CUFSM and GBTUL to study the cross-sectional and global buckling behaviour of Zee-shaped section. The numerical models are made using the S4R element, with simply supported end condition. The non-linear analysis including material, geometric non-linearity, and geometric imperfections, is conducted to predict the ultimate strength of the beam-column members. The numerical model was validated with the experimental results from the literature. Based on the validated model, the study is extended to develop axial—Moment (P-M1-M2) strength interaction surface for the selected member. The numerical study is conducted on the Zee-shaped member subjected to major, minor, and bi-axial moment. The effect of stress distribution due to combined load on the ultimate strength is examined, which forms the basis for the new design formulation for beam-column using direct strength method. The numerically generated strength surface was compared with beam-column prediction based on North American standard AISI S100-2016 specification.