Beam-column design of cold-formed steel semi-oval hollow non-slender sections

The design of cold-formed steel semi-oval hollow non-slender sections under combined compression and major axis bending in positive direction is studied in this paper. A non-linear finite element model was developed to simulate the beam-column tests. The model was validated against the available experimental results. An extensive parametric study on 140 short and long beam-columns loaded at different eccentricities as well as the corresponding 28 concentric loaded column counterparts was conducted covering a wide range of cross-section geometries, different member slenderness and loading eccentricities. The numerical results obtained in this study together with the available experimental results were compared with the design strengths predicted by the American Specification, Australian Standard as well as European Code and North American Specification. Reliability analysis was conducted to assess the reliability of different design rules. It is shown that the existing design rules provide reliable but quite conservative design strength predictions. Existing design rules are modified such that the accuracy of the design strength predictions is improved. Among the modified design methods, it is recommended to adopt the modified ANSI/AISC360 design method for cold-formed steel semi-oval non-slender sections subjected to combined compression and major axis bending in positive direction since it provides the most accurate design predictions.