An analytical hysteresis model to predict the small shear strain behavior of high-damping rubber isolation bearings

This paper proposes an analytical hysteresis model to predict the small shear strain behavior of high-damping rubber isolation bearings (HDR). The National Museum of Western Art (NMWA) in Tokyo, Japan was seismically upgraded in 1998 with a seismic isolation system. The design analyses for the upgrade utilized an existing hysteresis model for HDR isolation bearings. The model was capable of predicting the nonlinear properties of HDR isolators for deformations expected in large earthquakes. Since the upgrade, the acceleration response of the building has been recorded for a number of small earthquakes. The maximum deformation of the HDR isolators in the small earthquakes was below the strain range for which the hysteresis model had been developed, so the small deformation force-displacement relationships for the isolation system were identified from the observed building acceleration records and the original HDR hysteresis model was extended to cover a broad range of shear strain.