Multi-objective optimal design of a base-isolated structure equipped with a series-configured inerter–spring–damper system Part 1. Analytical model and frequency domain analysis of series-configured inerter–spring–damper system

摘要

It is well known that structural systems containing linear viscousrndamping (LVD) and rate-independent linear damping (RILD)rnwith the same damping ratio yield almost identical displacementrnresponses when subjected to ground motion. The damping forcerngenerated by RILD is higher (lower) than that of LVD at lowerrn(higher) frequencies, resulting in effective reduction ofrndisplacement and acceleration [1–3]. Thus, in low-frequencyrnstructures, RILD has the advantage of reducing excessiverndisplacements without increasing the floor response acceleration.rnAlthough the full benefits of RILD in low-frequency structuresrnare yet to be exploited, its non-causality poses major difficultiesrnfor time-domain analysis and for implementing RILD in actualrndevices. Nevertheless, causal representations of RILD have beenrndeveloped that enable time-domain analysis [3–6], and somernattempts have been made to use semi-active control to mimic thernbehavior of RILD [3, 7].