Numerical Analysis of Cold-Formed Built-Up Battened Steel Columns Under Eccentric Compressive Loading

This paper presents a 3D finite element model simulation using ABAQUS finite element software to investigate the behavior of steel battened beam columns under uniaxial loads. The columns consist of double-channel cold-formed slender open sections. The study highlighted the effects of various factors on the ultimate capacity of these beam-column members. By considering both global and local imperfections, the model focuses on the structural strength and performance of battened cold-formed steel columns made from built-up sections. These cold-formed steel (CFS) columns have a slenderness ratio ranging from 50 to 162. Axial loads are applied at the pin-ended support of the column, which comprises two cold-formed steel open-channel sections positioned at varying center-to-center distances. To validate the finite element models, their results were compared with relevant experimental data from the literature on similar geometries. The finite element analysis accounted for various factors, including different geometrical properties of column sections, slenderness ratios, nonlinear material properties of cold-formed steel sections, built-up section components, and initial geometric imperfections. Finally, the analysis results were compared to the predicted ultimate strengths according to both the North American Specification and European codes EC3. The findings show that the strength of battened columns is strongly influenced by the interaction of several factors, including the back-to-back distance of the two channels, depth-to-width ratios, number of battened, and overall column slenderness ratios.