Experiments are performed to validate the American Iron and Steel Institute's Direct Strength Method (DSM) for cold-formed steel design applied to a unique thin-walled 3-radius cold-formed steel oval tube. The tube segments make up a structural system for long span domes with surface areas over 20000 m~2. While it is expected that the dome design will be governed by overall global buckling under dead load, the compressive strength of the individual tubes experiencing local buckling is also checked. Strength prediction methods are limited for thin-walled steel tubes, especially for non-rectangular cross-sections, leaving engineers with few validated approaches for predicting axial capacity including local buckling. Stub column experiments are conducted to evaluate local buckling behavior and tested capacities are compared to DSM predictions employing finite strip elastic buckling analysis. It is confirmed with elastic buckling studies and the experiments that local buckling tendencies are reduced with radial curvature.
展开▼
