Performance of a passive rate-independent damping device in a seismically isolated multistory building

In the 2011 Great East Japan Earthquake, low-frequency components of ground motion brought long-duration shaking to high-rise buildings in mega-cities far from the epicenter, resulting in damage to their interior and exterior walls, and unsafe conditions for the building occupants. Rate-independent linear damping (RILD) has been suggested as a viable option for simultaneously reducing the excessive displacement and floor response acceleration of a low-frequency structure. While the majority of previous studies on RILD have mainly focused on theoretical and mathematical approaches, the practical applications of RILD have not been extensively investigated. In this regard, this study aims to experimentally and analytically investigate the physical implementation of RILD for the protection of a multistory low-frequency structure. The effectiveness of the proposed passive causal RILD device, comprising a Maxwell-type damper and negative stiffness, incorporated into a seismically isolated building was investigated based on real-time hybrid simulation. Under strong ground motions, the passive causal RILD device could greatly reduce the floor response accelerations in the seismically isolated structure, compared with a linear viscous damping device.