Design of cold-formed steel oval hollow section columns: Fid-Bau Portal

Design of cold-formed steel oval hollow section columns

Zhu, Ji-Hua / Young, Ben

Abstract This paper presents the numerical simulation and design of cold-formed steel oval hollow section columns. An accurate finite element model was developed to simulate the fixed-ended column tests of oval hollow sections. The material non-linearities obtained from tensile coupon tests as well as the initial local and overall geometric imperfections were incorporated in the finite element model. Convergence study was performed to obtain the optimized mesh size. A parametric study consisted of 100 columns was conducted using the verified numerical model. The failure modes of material yielding, local buckling and flexural buckling as well as interaction of local and flexural buckling were found in this study. The experimental column strengths and numerical results predicted by the parametric study were compared with the design strengths calculated using the current North American, Australian/New Zealand and European specifications for cold-formed steel structures. In addition, the direct strength method, which was developed for cold-formed steel members for certain cross-sections but not cover oval hollow sections, was used in this study. The reliability of these design rules was evaluated using reliability analysis.

Highlights ► Finite element analysis of cold-formed steel oval hollow section columns has been presented. ► 100 numerical data on oval hollow section columns were obtained and compared with design strengths. ► The design strengths were calculated using the current North American, Australian/New Zealand and European specifications as well as the direct strength method. ► The direct strength method is conservative and reliable for the design of both compact and slender oval hollow section columns.