Vertical Accelerations in Rolling Isolation Systems: Experiments and Simulations

Harvey, P. Scott

doi:10.1061/(asce)em.1943-7889.0001017

Cited by 16 publications

(24 citation statements)

References 31 publications

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“…Even though the pounding effect on the horizontal acceleration response of SSBs could be rationally ignored through experimental verification in this study, the design of two discontinuous slopes without an in‐between fillet might result in enlarged vertical acceleration responses for SSBs. Harvey's research 32 indicated that for RISs, in addition to the vertical ground motion input and the vertical projection of their horizontal relative acceleration response, the centripetal acceleration which is inversely proportional to the curvature radius designed for the fillet between two discontinuous slopes also plays an important role in their vertical acceleration response. Therefore, additional work is required to clarify this issue for SSBs in the future.…”

Section: Sloped Sliding‐type Bearings and Their Equation Of Motionmentioning

confidence: 99%

Analytical and experimental study on sloped sliding‐type bearings

Yang

Wang

Lin

et al. 2021

Structural Contr & Hlth

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Summary Seismic isolation design has been publicly accepted as one of the most effective strategies to reduce seismic threat to (or seismic demand for) the to‐be‐protected targets including building structures, infrastructure, and equipment. Recently, many studies have aimed to develop nonlinear seismic isolation systems, of which the sloped sliding‐type bearing can exhibit the nonlinear behavior by mechanically designing a simple slope for sliding motion. Therefore, this bearing does not have a fixed isolation frequency. In addition, it features that the seismic isolation performance is realized through the sliding mechanism, the inherent self‐centering capability is provided through the slope design, and the excellent and stable energy dissipation capability is contributed by the sliding friction. In this study, the equation of motion of the bearing is deduced first. Sensitivity analysis is then performed, and the results demonstrate that the maximum horizontal acceleration transmitted to the isolated superstructure is only dependent on two important design parameters‐sliding friction coefficients and sloping angles. In other words, the acceleration control performance of the bearing is irrelevant to different characteristics of external disturbance. Finally, shaking table tests were conducted to verify the effectiveness of the bearing and the accuracy of the numerical prediction.

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Section: Sloped Sliding‐type Bearings and Their Equation Of Motionmentioning

confidence: 99%

Analytical and experimental study on sloped sliding‐type bearings

Yang

Wang

Lin

et al. 2021

Structural Contr & Hlth

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“…The presence of the rubber has the objective of introducing a higher dissipation of energy between the base and the structure . Furthermore, by adopting a suitably elastomeric curved surface, it is possible to provide the recentering function, however, reducing the vertical accelerations that a geometry of this type entails …”

Section: Introductionmentioning

confidence: 99%

“…13,14 Furthermore, by adopting a suitably elastomeric FIGURE 1 Sketch of a full-scale model of rubber-layer roller-bearing isolator with (a) curved plates and (b) curved rubber ends curved surface, it is possible to provide the recentering function, 15,16 however, reducing the vertical accelerations that a geometry of this type entails. 17 Because the contact between the elastomer and the cylindrical elements is the key point of these devices, it has been necessary to understand this phenomenon in detail. 14 The achievement of this goal will enable the realization of the geometric optimization of the devices according to the load of the structure and the seismic stresses.…”

mentioning

confidence: 99%

Rolling devices for seismic isolation of lightweight structures and equipment. Design and realization of a prototype

Foti

2018

Struct Control Health Monit

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Summary The present paper shows the results of an experimental study on new rolling seismic isolators made with steel cylindrical elements arranged on two levels, interposed between flat rubber layers, and rolling in the same direction. It is a rather simplified version of an isolator designed to have the cylinders disposed on two levels, according to two directions perpendicular to one another in the horizontal plane, in order to uncouple any component of the seismic force. In the original basic idea, the rolling planes present a concave surface with a high radius of curvature for recentering capabilities of the device. The rolling of the cylinders allows the isolation of the structure uncoupling the motion of the structure by the ground motion, although the rubber layers have to activate a viscous dissipation process, thanks to the steel‐rubber contact. A prototype of the simplified version of the device has been realized and tested to obtain the hysteresis behavior and the equivalent viscous damping under increasing values of the axial preload, either with glued or vulcanized rubber layers. The results have been finally discussed also to identify the possible future developments and improvements of the proposed device.

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“…Moreover, the double rolling isolation systems were proposed to increase the limit of horizontal displacement. [15][16][17] It is worthy of noting that the rolling isolation systems can isolate the horizontal vibration only, but the vibration-sensitive optical device is highly sensitive to three-axis vibrations and its bearable maximum acceleration is 0.2 g. Therefore, it is important to isolate the three-axis vibrations simultaneously.…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, the double rolling isolation systems were proposed to increase the limit of horizontal displacement. 15–17…”

Section: Introductionmentioning

confidence: 99%

Performance of a low-frequency hybrid vibration isolation platform for vibration-sensitive devices

Xie

Diao

et al. 2018

Journal of Low Frequency Noise, Vibration and Active Control

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For preventing the fragile optical communication devices from malfunction caused by the low-frequency seismic excitation, a novel three-dimensional hybrid isolation platform is proposed in this paper. To isolate the horizontal and vertical vibrations simultaneously, the platform is designed as a combination of a rolling isolation system and four threeparameter isolators with active damping. By deriving the governing equations of the three-parameter isolators and the profile of the concave rolling surface, the dynamic model of the whole platform is constructed. Numerical results indicate that the isolation platform has an effective suppression of the horizontal and vertical vibrations. To verify the isolation performance of the hybrid isolation platform, an experiment is conducted in the targeting frequency range. Compared to the amplification factor of 6.2 dB of the three-parameter isolator, the test results exhibit that the hybrid isolation shows no amplification effect in the vertical direction, and the root mean square value of acceleration responses can be decreased by more than 65% in the frequency range of 0-32 Hz. In the horizontal direction, the reduction of the root mean square value of acceleration responses is up to 85% in the same frequency range.

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Vertical Accelerations in Rolling Isolation Systems: Experiments and Simulations

Cited by 16 publications

References 31 publications

Analytical and experimental study on sloped sliding‐type bearings

Analytical and experimental study on sloped sliding‐type bearings

Rolling devices for seismic isolation of lightweight structures and equipment. Design and realization of a prototype

Performance of a low-frequency hybrid vibration isolation platform for vibration-sensitive devices

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