We have focused on the U-shaped device, which has excellent repetitive energy absorption performance, and have been investigating its applicability to steel-based industrialized housings. In the previous papers, we clarified the influence of the shape factor of the U-shaped device on its mechanical performance3) and the cyclic deformation behavior under constant amplitude loading5). In fatigue performance evaluation that targets only constant amplitude loading, it is difficult to estimate fatigue characteristics for various amplitudes like actual earthquake motion. Therefore, in this paper, we attempt to estimate the fatigue characteristics at multi-stage amplitude using the formulation results obtained from constant amplitude.
