Improving the dynamic performance of base-isolated structures via tuned mass damper and inerter devices: A comparative study

Abstract

The dynamic performance of base-isolated buildings can be improved by introducing a tuned mass damper (TMD) at basement, below the isolation floor where most of the earthquake-induced displacement demand is concentrated. In order to enhance the effectiveness of the TMD without simultaneously amplifying the relevant mass ratio, the use of supplemental inertial mass dampers has been envisaged by the authors and other authors in earlier studies. These schemes exploit the mass-amplification effect of the inerter, a twoterminal device whose generated force is ideally proportional to the relative acceleration between its terminals. In this paper, we present a review along with a systematic comparative study of six different strategies proposed in the literature, each one featuring a specific combination of mass-spring-dashpot elements arranged in series or in parallel with an inerter for the displacement mitigation of base-isolated structures. Frequency-response functions of each model are derived in closed form. Optimal design is based on a common strategy, considering a white-noise random process as seismic input, by minimization of the displacement variance but with an eye also for the superstructure acceleration (associated with forces arising in the superstructure) and for the TMD stroke. Then, the seismic performance of the six systems is assessed considering an ensemble of 52 natural earthquake ground motions, by comparing several response indicators including TMD stroke, deformation of the baseisolation floor, superstructure acceleration, interstory drifts, base shear, and reactions associated with spring, oil damper, and inertial damper supporting the TMD, which are significant for outlining preliminary economic assessments.

Damping enhancement principle of inerter system

“…1,2 Many studies have been conducted to propose various device and structural control approaches in order to reduce the vibration response produced by earthquakes, wind, etc. [3][4][5][6][7] As a recently introduced mechanical element for structural control, the inerter has attracted an increasing amount of attention and has been studied in different fields, from the improved suspension system in mechanical [8][9][10][11][12] and railway engineering 13,14 to the protection of building structures, [15][16][17][18][19][20][21][22][23][24][25] storage tanks, [26][27][28] wind turbine towers, 29,30 platforms, 31 and performanceimproved cables [32][33][34][35] and isolation systems [36][37][38][39][40][41][42][43][44][45] in civil engineering. An inerter is a type of two-terminal inertia element, and its relative motion can be produced between the two termi...…”

Performance‐based seismic design of tuned inerter dampers

“…Other configurations involving inerters, such as Ikago et al who introduced a tuned viscous mass damper for civil engineering applications, have been proposed in the literature and are discussed by Zhang et al In addition to the earlier studies demonstrating how TIDs can be designed to improve the behaviour of host structures, such as multistorey buildings or stay cables, TIDs have also been tested experimentally using dynamic substructuring emphasising their feasibility and applicability. Besides civil engineering design applications,() inerter‐based vibration absorbers have been considered in the context of a range of practical applications, such as vehicle suspensions,() train suspensions,() or aircraft landing gears . The majority of the studies on optimal control devices of the kind presented herein consider frequency or time‐domain analyses that involve the calculation of multiple structural system's response.…”

Effect of inerter for seismic mitigation comparing with base isolation

“…13 When the mass in TMDI is entirely replaced by the inerter, the TMDI system becomes the tuned inerter damper system, 15,16 which has been studied in many aspects. [17][18][19] Recently, an alternative that combining the conventional BIS with the TMDI proposed by De Domenico and Ricciardi 20,21 has been proved to be a more effective vibration control strategy with the comparison of BIS coupled with TMD as well as the comparison of BIS with supplementary damping.…”