Seismic control of single-degree-of-freedom structure using tuned viscous mass damper

Abstract: In seismic base isolation, most of the earthquake‐induced displacement demand is concentrated at the isolation level, thereby the base‐isolation system undergoes large displacements. In an attempt to reduce such displacement demand, this paper proposes an enhanced base‐isolation system incorporating the inerter, a 2‐terminal flywheel device whose generated force is proportional to the relative acceleration between its terminals. The inerter acts as an additional, apparent mass that can be even 200 times higher than its physical mass. When the inerter is installed in series with spring and damper elements, a lower‐mass and more effective alternative to the traditional tuned mass damper (TMD) is obtained, ie, the TMD inerter (TMDI), wherein the device inertance plays the role of the TMD mass. By attaching a TMDI to the isolation floor, it is demonstrated that the displacement demand of base‐isolated structures can be significantly reduced. Due to the stochastic nature of earthquake ground motions, optimal parameters of the TMDI are found based on a probabilistic framework. Different optimization procedures are scrutinized. The effectiveness of the optimal TMDI parameters is assessed via time history analyses of base‐isolated multistory buildings under several earthquake excitations; a sensitivity analysis is also performed. The enhanced base‐isolation system equipped with optimal TMDI attains an excellent level of vibration reduction as compared to the conventional base‐isolation scheme, in terms not only of displacement demand of the base‐isolation system but also of response of the isolated superstructure (eg, base shear and interstory drifts); moreover, the proposed vibration control strategy does not imply excessive stroke of the TMDI.

TL;DR: In this paper, the optimal design and performance evaluation of a Tuned Mass Damper Inerter (TMDI) to reduce dynamic vibrations were discussed. But the authors focused not exclusively on the primary structure response but also on the secondary one.

TL;DR: In this article, the authors considered an optimum tuned mass damper-inerter (TMDI) design framework accommodating the above effects while accounting for parametric uncertainty to the host structure properties, modeled as a linear multi degree of freedom system, and modeled as stationary colored noise.

TL;DR: In this article, a two-terminal mechanical element, dubbed inerter, was proposed based on the force-current analogy, offering many potentials for upgrading conventional structural vibration control systems.

TL;DR: In this paper, the authors review the recent and rapid developments in semi-active structural control and its implementation in full-scale structures, and present an alternative to active and hybrid control for structural vibration reduction.

Abstract: Some practical issues associated with the application of viscoelastic (VE) dampers to building structures for seismic performance enhancement are studied in this paper. A sequential procedure is developed for optimally placing VE dampers to structures, based on the concept of degree of controllability. This optimal placement procedure is then experimentally verified using a five‐story steel model structure. Economical use of the VE dampers is made possible by adding them to the optimal locations found by this procedure, as is clearly demonstrated by the numerical examples and experimental results presented in the paper. A design procedure is also presented by which damper dimensions, number, and locations needed to achieve desired level of additional damping can be determined in accordance with the structural parameters and structural‐response reduction requirement. Design of VE dampers for a 24‐story steel frame is presented as an example, showing the complete design procedure for applying VE dampers to ...

TL;DR: Tuned mass dampers attached to single degree-of-freedom systems representing tall buildings are studied in this paper, where system equations are formulated and solved for various input forcing functions, and the parameters of the damper are varied to study the response reduction.