Adaptive causal realization of rate-independent linear damping

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

“…Conventional control devices, such as fluid and hysteretic dampers, are used in reducing the displacement and floor response acceleration; however, this results in a trade-off relationship, in which the increase in the number of conventional dampers can reduce excessive displacement while compromising the floor response acceleration. [1][2][3] Rateindependent linear damping (RILD) is an ideal linear model for simultaneously reducing excessive displacement and floor response accelerations in low-frequency structures. Particularly, this model obtains the direct displacement control through a resistive force that is proportional to the response displacement and in phase with the velocity.…”

“…[41][42][43] In the RTHS method, only critical components, such as rate-dependent components, are physically tested, whereas the remaining elements of the structure are simulated in the numerical domain. Keivan et al 2 conducted RTHS on a 14-story interstory isolation building equipped with a semi-active damper to investigate the performance of an adaptive control algorithm to mimic the behavior of RILD. However, to the best of the authors' knowledge, there is yet to be an experimental study on multistory low-frequency structures equipped with passive RILD devices.…”

“…With the increasing number of seismically isolated high‐rise buildings, the possible excessive displacement in low‐frequency structures induced by low‐frequency components in an extreme seismic event has attracted considerable attention. Conventional control devices, such as fluid and hysteretic dampers, are used in reducing the displacement and floor response acceleration; however, this results in a trade‐off relationship, in which the increase in the number of conventional dampers can reduce excessive displacement while compromising the floor response acceleration 1–3 . Rate‐independent linear damping (RILD) is an ideal linear model for simultaneously reducing excessive displacement and floor response accelerations in low‐frequency structures.…”

Unifying causal model of rate‐independent linear damping for effectively reducing seismic response in low‐frequency structures

“…Keivan et al 18,19 proposed semi-active control methods to mimic the behavior of RILD using a first-order causal digital filter, which was further passively realized using a mechanical system comprising a negative stiffness element coupled in parallel with a Maxwell element 2 . In this study, to improve the approximation of the dissipation behavior of RILD, a novel model is proposed by generalizing the first-order causal filter to a fractional-order causal filter.…”

Experimental study of earthquake input energy of low‐frequency structures equipped with a passive rate‐independent damping device

“…Rate-independent linear damping (RILD) is found to be an ideal linear model for simultaneously reducing excessive displacement and floor response accelerations because it achieves direct control of displacement via a resistive force that is proportional to the response displacement and in phase with the velocity. [1][2][3] RILD is a non-causal element, [4][5][6] which hinders its physical implementation. Nevertheless, many researchers have investigated the causal approximation of RILD.…”