Numerical modeling and design of cold-formed steel oval hollow section compression members

The numerical analysis and design of cold-formed steel compression members of oval hollow sections have been investigated. A finite element model was developed to simulate the existing tests on fixed-ended columns of oval hollow sections. The failure modes observed from the tests included material yielding, local buckling and flexural buckling as well as interaction of local and flexural buckling. The finite element model was developed using ABAQUS. The material non-linearities obtained from tensile coupon tests as well as the initial local and overall geometric imperfections were incorporated in the model. Convergence study was performed to obtain the optimized mesh density. A parametric study included 100 columns was conducted using the verified numerical model. 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 carbon steel members for certain qualified cross sections, was also used to predict the design strengths for the oval hollow sections.