A series of quasi-static cyclic tests of cold-formed circular hollow section members (which is used in steel tower structures) with 20 or 40 of the slenderness ratio and 60 to 80 of the diameter-to-thickness ratio was performed to investigate the buckling behavior and the cumulative deformation capacity. A modified Shibata-Wakabayashi hysteresis model was proposed based on the experimental result. Moreover, finite element analysis was performed to analyze the local strain and to validate the existing simple evaluation method of fracture initiation on the local buckling part of cold-formed circular hollow section members.
