Second‐mode tuned mass dampers in base‐isolated structures for reduction of floor acceleration

Shi, Yundong; Saburi, Kazuhiro; Nakashima, Masayoshi

doi:10.1002/eqe.3097

Cited by 9 publications

(5 citation statements)

References 23 publications

(49 reference statements)

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“…It is in favor of base isolation but, unfortunately, not the case in practice because, although the desired isolation period may be achieved by proper design, an increase in the capacity of the dampers in the isolator always leads to a decrease in the equivalent isolation period by adding some stiffness to the isolator for a given isolation period T i . This is true no matter whether metal or oil dampers are used 30,31 . To this end, there is a need to develop new strategies for maximizing the energy dissipation of a BI system without reducing its flexibility at the isolator.…”

Section: Parametric Analysis By Numerical Simulationmentioning

confidence: 99%

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Limitation of base isolation in protecting freestanding contents in buildings

Wang

Huang

2023

Earthq Engng Struct Dyn

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Seismic base isolation performs well in protecting the drift‐ and acceleration‐sensitive elements in buildings, while its effectiveness in reducing the velocity response and thus protecting velocity‐sensitive elements remains unclear. Through laboratory tests and numerical simulations, this paper shows that base isolation does not adequately control the floor velocity to the same level as the drift and acceleration, particularly on lower floors and under pulse‐like ground motions with rich long‐period contents. This limitation is attributed to the frequency‐insensitive velocity spectra of the ground motions and the significant difference in the mode shapes between base‐isolated and fixed‐base buildings. This limitation is demonstrated by comparing the loss ratios of rocking‐dominated freestanding contents due to overturning in base‐isolated buildings and their fixed‐base counterparts. By assuming a uniform distribution of randomly generated freestanding contents and adopting different overturning fragility models, the results show that the base isolation may be ineffective in reducing the loss ratio of rocking‐dominated contents in a building and may even adversely increase the loss ratio, especially for large objects, and when low‐ and moderate‐seismic intensities are concerned.

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Section: Parametric Analysis By Numerical Simulationmentioning

confidence: 99%

“…This is true no matter whether metal or oil dampers are used. 30,31 To this end, there is a need to develop new strategies for maximizing the energy dissipation of a BI system without reducing its flexibility at the isolator.…”

Section: Effects Of Additional Damping In the Isolatormentioning

confidence: 99%

Limitation of base isolation in protecting freestanding contents in buildings

Wang

Huang

2023

Earthq Engng Struct Dyn

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“…D is the position vector of the damping force; and F d is the damping force of the VOD, which is given in equation (29). The damping matrix of the superstructure is considered proportional to the superstructure's stiffness matrix [11]:…”

Section: Modeling Of a Base-isolated Structure Equipped With A Vodmentioning

confidence: 99%

“…Passive dampers are widely accepted in practice for structures under earthquakes all over the world for its reliable, efficient and cost-effective features [8][9][10][11]. The performance of passive dampers used in base isolations has been validated through recorded earthquakes and experimental studies.…”

Section: Introductionmentioning

confidence: 99%

A frequency-dependent variable-damping control based variable-orifice damper for smart base-isolation system

Li¹,

Wen²,

Shi³

et al. 2022

Smart Mater. Struct.

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Damping devices are commonly used in the isolation layer of base-isolated structures to provide additional damping to control the structural responses. Normally, large damping for the isolation layer is useful to minimize the resonance effect under low-frequency ground motions, and small damping is preferred to reduce the structural responses under high-frequency ground motions. Traditional passive dampers are widely adopted in engineering practice. Due to the fixed damping characteristic, however, the performance of base-isolated structures with passive dampers cannot stay optimal under ground motions with different frequency characteristics. To realize an optimal control of base-isolated structures, semi-active control has been increasingly valued for its efficiency and intelligence to adjust the damping characteristics based on feedback information from the structure and ground motion. However, a large number of sensors and hardware components are required for semi-active control, which makes the system complex and costly. In this paper, a variable-orifice damper (VOD) for smart base-isolation system is proposed. The VOD can adaptably adjust its damping according to the frequency of the ground motion without additional power or sensors. Theoretical analysis and sinusoidal excitation tests were carried out to investigate the behavior of VOD. A series of numerical simulations of a base‐isolated structure equipped with the proposed VOD and subjected to ground motions are also conducted. A semi-active control with ON-OFF strategy, and two passive controls (passive-on and passive-off) are conducted for comparison. The simulation results show that the VOD can result in an optimal control under ground motions with different frequency characteristics.

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“…Further, to control base-isolated structure acceleration without producing a significant rise in displacement, supplemental seismic control strategies can be used (Shi et al, 2018;.…”

Section: Introductionmentioning

confidence: 99%

Optimal seismic response using a Passive Tuned Mass Damper Inerter (TMDI)

Djerouni

Ounis

Athamnia

et al. 2020

J. build. mater. struct.

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The latest earthquakes history shows that resistant conception, safe and economical structures are a daily challenge for structural engineers. Among the newest vibration control devices figures the inerter which is a device which can develop a large fictive mass (it consists of a mass amplification effect) using rotational inertia. In this research work, the effectiveness of a traditional passive tuned mass damper (TMD) is compared with a tuned mass damper inerter (TMDI) which consists generally of tuned mass damper coupled with an Inerter. Both devices are used to control a base-isolated structure vibration submitted to several seismic records. In This study, a base-isolated structure of six stories (6 DOF) was equipped with (TMD) and (TMDI) and a time history analysis were performed under different earthquake records (El Centro, Kobe, Kocaeli). The mathematical model of the building is established in MATLAB Simulink. The simulation results illustrated he robustness, performance and effectiveness of the structure equipped with a (TMDI). The dynamical parameters of interest were base and top displacement as well as the base shear force and peak inerter force produced.

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Second‐mode tuned mass dampers in base‐isolated structures for reduction of floor acceleration

Cited by 9 publications

References 23 publications

Limitation of base isolation in protecting freestanding contents in buildings

Limitation of base isolation in protecting freestanding contents in buildings

A frequency-dependent variable-damping control based variable-orifice damper for smart base-isolation system

Optimal seismic response using a Passive Tuned Mass Damper Inerter (TMDI)

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