In recent years in Japan, various research and developments using oil dampers have been carried out to find a way to suppress the displacement of the seismic isolation structure in response to a large-amplitude seismic motion exceeding design specifications. As a countermeasure, the authors have proposed a velocity-dependent, multi-staged oil damper. For the performance of the seismic isolation device responds to a large-amplitude seismic motion, the repeated deformation dependence of the oil damper has been evaluated using time history response analysis by changing the damping coefficient from moment to moment and so far, there has been little research of detailed evaluation. In this paper, we report about a new function newly introduced in OpenSees, which takes into account the repeated deformation dependence of the oil damper, and verified the response suppression effect by the proposed damper, while conducting a seismic response analysis for the test seismic building. As a result, it is concluded that the velocity-dependent, multi-staged oil damper works effectively when the repeated deformation dependence of the seismic isolation device is taken into consideration.
