Abstract
This paper presents an analytical hysteresis model of horizontal force-deformation relationship for lead dampers to evaluate the safety of seismic isolation system exposed to long-period earthquake motion. Dynamic loading tests with full-scale dampers were conducted. Yielding strength of damper declined with increase in accumulative deformation, however, it showed rise up temporarily when deformation amplitude was changed on sinusoidal horizontal loading. The analytical model can consider these features. Horizontal load of the test given response displacement motions at isolation layer obtained by a seismic time-history analysis using long-period earthquake motion was in good agreement with one calculated from the model.
