Case history building structural vibration isolation for 500 Atlantic Avenue

2006 ◽  
Vol 120 (5) ◽  
pp. 3207-3207
Author(s):  
Gregory Tocci ◽  
George Wilson ◽  
James Phillips ◽  
Gladys Unger ◽  
James Moore
Keyword(s):  
Case History ◽  
Vibration Isolation ◽  
Structural Vibration

scholarly journals Research on dynamic characteristics of plate under pedestrian excitation based on Newmark-β

2018 ◽  
Vol 37 (4) ◽  
pp. 682-699
Author(s):  
Xinfang Ge ◽  
Weirong Wang ◽  
Wei Yuan
Keyword(s):  
Rectangular Plate ◽  
Dynamic Characteristics ◽  
Vibration Isolation ◽  
Great Influence ◽  
Interaction Model ◽  
Vertical Direction ◽  
Structural Vibration ◽  
Normal Walking ◽  
Plate Structure ◽  
Pedestrian Excitation

Development of micro and ultra-precision machining, precision instruments and equipment, precision assembly and testing has put forward more and more high requirements to vibration isolation on environmental elements, especially the pedestrian excitation generated by workers' normal walking. Therefore, it is very important to study the pedestrian excitation's influence on vibration characteristics of precision instruments and equipment. In this study, dynamic model including mathematical model of pedestrian excitation, interaction model between pedestrian and rectangular plate structure, the human–plate coupled dynamic equation in vertical direction of pedestrian–plate structure was established. And then we use the Newmark-β method to solve the time-domain step-by-step integration of the first four order modes' dynamic equations and study the influence of the linear notion trajectory along the central axis direction on the dynamic characteristics of the rectangular plate. By simulation, we discussed plate structure response under different conditions, including plate structure displacement and acceleration response under the single person excitation with different velocities, under normal walking velocity with different number of pedestrians and under this case of different distance between two pedestrians. The results show that the structural vibration induced by pedestrian excitation has great influence on dynamic characteristics of plate.

Passive Isolation by Nonlinear Boundaries for Flexible Structures

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Xiao-Ye Mao ◽  
Hu Ding ◽  
Li-Qun Chen
Keyword(s):  
Vibration Isolation ◽  
Flexible Structures ◽  
Linear Structure ◽  
Response Prediction ◽  
Structural Vibration ◽  
Original Structure ◽  
Analytic Method ◽  
Stress Control ◽  
Passive Isolation ◽  
Passive Technique

A simple passive technique of vibration isolation for flexible structures by nonlinear boundaries is investigated, which to our best knowledge is the first study of its kind reported in the literature. The equations of the structure are derived with Hamilton’s principle. An iterative analytic method is investigated to improve the accuracy of the response prediction. The effect of nonlinear boundaries of the structure is studied compared with the linear structure. It is found that stronger nonlinearities in the boundary make the system more stable. Analytical and simulation results show that nonlinear boundaries can significantly reduce the vibration and stress of flexible structures. It is important to point out that with the help of nonlinear boundaries, structural vibration and stress control can be achieved without altering the original structure.

scholarly journals Application of Tuned Mass Dampers for Structural Vibration Control: A State-of-the-art Review

2020 ◽  
Vol 6 (8) ◽  
pp. 1622-1651
Author(s):  
Fatemeh Rahimi ◽  
Reza Aghayari ◽  
Bijan Samali
Keyword(s):  
Vibration Control ◽  
Control Systems ◽  
Performance Optimization ◽  
Structural Control ◽  
Vibration Isolation ◽  
Hybrid Control ◽  
Structural Vibration ◽  
Tuned Mass Dampers ◽  
Advantages And Disadvantages ◽  
Hybrid Control Systems

Given the burgeoning demand for construction of structures and high-rise buildings, controlling the structural vibrations under earthquake and other external dynamic forces seems more important than ever. Vibration control devices can be classified into passive, active and hybrid control systems. The technologies commonly adopted to control vibration, reduce damage, and generally improve the structural performance, include, but not limited to, damping, vibration isolation, control of excitation forces, vibration absorber. Tuned Mass Dampers (TMDs) have become a popular tool for protecting structures from unpredictable vibrations because of their relatively simple principles, their relatively easy performance optimization as shown in numerous recent successful applications. This paper presents a critical review of active, passive, semi-active and hybrid control systems of TMD used for preserving structures against forces induced by earthquake or wind, and provides a comparison of their efficiency, and comparative advantages and disadvantages. Despite the importance and recent advancement in this field, previous review studies have only focused on either passive or active TMDs. Hence this review covers the theoretical background of all types of TMDs and discusses the structural, analytical, practical differences and the economic aspects of their application in structural control. Moreover, this study identifies and highlights a range of knowledge gaps in the existing studies within this area of research. Among these research gaps, we identified that the current practices in determining the principle natural frequency of TMDs needs improvement. Furthermore, there is an increasing need for more complex methods of analysis for both TMD and structures that consider their nonlinear behavior as this can significantly improve the prediction of structural response and in turn, the optimization of TMDs.

Smart Materials-Based Structural Vibration Isolation for Minimizing Product Quality Variation Using H∞-Based Optimal Control

Manufacturing ◽  
2002 ◽  
Author(s):  
J. A. Turso ◽  
J. T. Roth
Keyword(s):  
Smart Materials ◽  
Vibration Isolation ◽  
Piezoelectric Actuators ◽  
Structural Vibration ◽  
Band Model ◽  
Manufacturing Equipment ◽  
Patch Type ◽  
Simulation Testing ◽  
Nominal Performance ◽  
Piezoelectric Actuators And Sensors

An H∞-Based optimal vibration isolation system using patch-type piezoelectric actuators and sensors, suitable for application on high-precision manufacturing equipment that is being affected by external disturbances, has been designed. Reductions of the force transmitted through the structure range from approximately 5 to 30 dB in the frequency band of interest. Robust stability, nominal performance and robust performance have all been verified using the structured singular value, μ, and simulation testing for the set of plants within a derived uncertainty set. In addition, the H∞ controller is compared to an LQG-optimal controller designed for the same structure. The LQG controller, while achieving nominal performance comparable to the H∞ controller and being of significantly lower order, was shown to be unstable via μ-analysis and simulation testing. Thus, the LQG design should not be applied to a machine where there is significant in-band model uncertainty. Use of light-weight patch-type piezoelectric actuators and sensors provides a low-cost, easily-installable way of applying this technique to manufacturing equipment requiring isolation from low-frequency disturbances.

scholarly journals Isolation effects of vehicle-induced vibration tested by integral floating method

2021 ◽  
Vol 13 (9) ◽  
pp. 168781402110449
Author(s):  
Hao Li ◽  
Weiguo Yang ◽  
Pei Liu ◽  
Xiaoguang Zou ◽  
Meng Wang
Keyword(s):  
Vibration Isolation ◽  
Field Measurements ◽  
Dynamic Responses ◽  
Structural Vibration ◽  
Vibration Source ◽  
Frequency Range ◽  
Cultural Center ◽  
Time Frequency ◽  
Isolation Methods ◽  
Isolation Effects

A set of integral floating vibration isolation methods was developed in this study to remedy the lack of effective measures for over-track buildings. The effect of vibration isolation pads was investigated experimentally; the resulting field measurements were used to determine the time-frequency dynamic responses of vehicle-induced vibration and isolation effects. The characteristics of the vibration source appear to significantly affect the frequency domain distribution of vibration inside the building. When no vibration isolation measures are taken, the internal vibration of the cultural center exceeds the limit. BSW vibration isolation pads R480, R550, and R800 are effective in the frequency range of 16–80 Hz. The vibration isolation level in the Z direction is between 5.6 and 7.3 dB. After floating vibration isolation treatment, the maximum Z vibration level of the cultural center is 56.4 dB in daytime hours and 52.9 dB at night, which satisfies the relevant standard. The proposed method is shown to effectively hinder the structural vibration caused by subways on surrounding buildings.

scholarly journals Bandgaps and vibration isolation of local resonance sandwich-like plate with simply supported overhanging beam

2021 ◽  
Vol 42 (11) ◽  
pp. 1555-1570
Author(s):  
Chenxu Qiang ◽  
Yuxin Hao ◽  
Wei Zhang ◽  
Jinqiang Li ◽  
Shaowu Yang ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Vibration Isolation ◽  
Damping Ratio ◽  
Core Layer ◽  
Lower Surface ◽  
Structural Vibration ◽  
Local Resonance ◽  
Simply Supported ◽  
Finite Element Software ◽  
Linear Spring

AbstractThe concept of local resonance phononic crystals proposed in recent years provides a new chance for theoretical and technical breakthroughs in the structural vibration reduction. In this paper, a novel sandwich-like plate model with local resonator to acquire specific low-frequency bandgaps is proposed. The core layer of the present local resonator is composed by the simply supported overhanging beam, linear spring and mass block, and well connected with the upper and lower surface panels. The simply supported overhanging beam is free at right end, and an additional linear spring is added at the left end. The wave equation is established based on the Hamilton principle, and the bending wave bandgap is further obtained. The theoretical results are verified by the COMSOL finite element software. The bandgaps and vibration characteristics of the local resonance sandwich-like plate are studied in detail. The factors which could have effects on the bandgap characteristics, such as the structural damping, mass of vibrator, position of vibrator, bending stiffness of the beam, and the boundary conditions of the sandwich-like plates, are analyzed. The result shows that the stopband is determined by the natural frequency of the resonator, the mass ratio of the resonator, and the surface panel. It shows that the width of bandgap is greatly affected by the damping ratio of the resonator. Finally, it can also be found that the boundary conditions can affect the isolation efficiency.

Analytical Study of 1D Periodic Foundations for Structural Vibration Isolation

2015 ◽  
Author(s):  
W. Witarto ◽  
Y. Yan ◽  
S. J. Wang ◽  
Y. L. Mo ◽  
K. C. Chang ◽  
...  
Keyword(s):  
Seismic Wave ◽  
Vibration Isolation ◽  
P Wave ◽  
General Idea ◽  
Structural Vibration ◽  
Earthquake Ground Motion ◽  
Frequency Content ◽  
Analysis Model ◽  
Main Frequency ◽  
The Past

The application of periodic foundations for structural vibration isolation has been intensively studied in the past decade. The ability of the periodic foundation to block the seismic wave on certain frequency ranges has put this kind of foundations as a prosperous next generation of seismic isolators. This paper first describes general idea of basic theory of one dimensional (1D) periodic foundation. The parametric studies based on the material and the geometric properties conducted in the past are discussed. The experimental tests on 1D periodic foundation are reported as well. Based on the promising results of the past research, 1D periodic foundations have been regarded as one of the simplest, yet effective foundation to block the seismic wave in all directions. In addition to the review of the existing studies, enhanced analyses of 1D periodic foundations have been performed and are presented in this paper. Finite element analysis model of 1D periodic foundations with a three story steel frame as the superstructure was utilized for the parametric study. The study was conducted under both Shear Wave (S-Wave) and Primary Wave (P-Wave). The independent variables include the number of unit cells in the periodic foundation, the foundation and superstructure interaction, and the main frequency content of earthquake ground motion. It is found that the main frequency content of the earthquake and the natural frequency of the super structure-periodic foundation system play the major role in the superstructure response. While the number of unit cell affect the superstructure response, the effect is not as significant as the aforementioned.

Inner structural vibration isolation method for a single control moment gyroscope

2016 ◽  
Vol 361 ◽  
pp. 78-98 ◽  
Author(s):  
Jingrui Zhang ◽  
Zixi Guo ◽  
Yao Zhang ◽  
Liang Tang ◽  
Xin Guan
Keyword(s):  
Vibration Isolation ◽  
Structural Vibration ◽  
Isolation Method ◽  
Control Moment Gyroscope ◽  
Control Moment
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