Seismic control of base-isolated structures using rate-independent damping devices

Abstract

Rate-independent linear damping (RILD) is a viable option for addressing excessive displacement challenges in low-frequency structures, particularly those subjected to ground motions containing many low-frequency components. RILD can mitigate the floor response acceleration of base-isolated structures more effectively than linear viscous damping (LVD) because of the larger damping force generated in the low-frequency region. However, RILD is an ideal element that exhibits noncausal characteristics. Many researchers have attempted to find approaches to realizing RILD, including both theoretical and mathematical investigations. Thus far, the physical realization of RILD remains challenging. In this study, a tuned inertoviscous-negative-stiffness Maxwell−Weichert (IvNsMW) model and a tuned inerter-viscous damper-negative-stiffness Maxwell−Weichert (IVdNsMW) model are proposed to promote progress in the application of RILD. These models differ in terms of the connection between the inerter and viscous damper. A direct design method is presented to determine the coefficients of these two devices. The efficiency of the proposed RILD-based devices for seismic control of low-frequency structures was examined using a multistory base-isolated structure. The results demonstrate that the proposed RILD devices are promising tools for both displacement and acceleration control of low-frequency structures.