Vibration Suppression Performance of a Desktop Vibration Isolator Supported by Four Air Spring

2017 ◽  
Author(s):  
Yuichi Baba ◽  
Kento Onishi ◽  
Toshihiko Asami
Keyword(s):  
Support System ◽  
Vibration Isolation ◽  
Vibration Suppression ◽  
Theoretical Calculations ◽  
Small Diameter ◽  
Measuring Instruments ◽  
Vibration Isolator ◽  
Air Spring ◽  
Damping Force ◽  
Vibration Isolators

Desktop vibration isolators are often used as precision measuring instruments. This article discusses the accuracy of performance prediction methods for vibration isolators elastically supported by four air springs. Each air spring possesses a reservoir tank to ensure the natural frequency of the support system remains low and to provide adequate damping force. For practical use, air springs and reservoir tanks should be installed in separate locations and connected by a small-diameter pipe because desktop isolators must be thin. Our previous studies have shown that there is a secondary resonance point in systems supported by air springs with long pipes and reservoir tanks and that it is not simple to theoretically calculate the amplitude and frequency at this point because this type of air spring support system has nonlinear characteristics. In this study, the change in the vibration isolation performance of a desktop vibration isolator with the length of the pipe connecting the main air tank and the reservoir tank of an air spring-supported system was examined experimentally and approximated using theoretical calculations.

Energy flow and performance evaluation of inerter-based vibration isolators mounted on finite and infinite flexible foundation structures

2022 ◽  
Vol 14 (1) ◽  
pp. 168781402110704
Author(s):  
Zhuang Dong ◽  
Jian Yang ◽  
Chendi Zhu ◽  
Dimitrios Chronopoulos ◽  
Tianyun Li
Keyword(s):  
Power Flow ◽  
Vibration Isolation ◽  
Vibration Suppression ◽  
Flow Behavior ◽  
Flexible Beam ◽  
Vibration Isolators ◽  
Force Transmissibility ◽  
And Performance ◽  
Flexible Foundation ◽  
Isolation Performance

This study investigates the vibration power flow behavior and performance of inerter-based vibration isolators mounted on finite and infinite flexible beam structures. Two configurations of vibration isolators with spring, damper, and inerter as well as different rigidities of finite and infinite foundation structures are considered. Both the time-averaged power flow transmission and the force transmissibility are studied and used as indices to evaluate the isolation performance. Comparisons are made between the two proposed configurations of inerter-based isolators and the conventional spring-damper isolators to show potential performance benefits of including inerter for effective vibration isolation. It is shown that by configuring the inerter, spring, and damper in parallel in the isolator, anti-peaks are introduced in the time-averaged transmitted power and force transmissibility at specific frequencies such that the vibration transmission to the foundation can be greatly suppressed. When the inerter is connected in series with a spring-damper unit and then in-parallel with a spring, considerable improvement in vibration isolation can be achieved near the original peak frequency while maintaining good high-frequency isolation performance. The study provides better understanding of the effects of adding inerters to vibration isolators mounted on a flexible foundation, and benefits enhanced designs of inerter-based vibration suppression systems.

On the Effects of Mistuning a Force-Excited System Containing a Quasi-Zero-Stiffness Vibration Isolator

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Ali Abolfathi ◽  
M. J. Brennan ◽  
T. P. Waters ◽  
B. Tang
Keyword(s):  
Vibration Isolation ◽  
Dynamic Stiffness ◽  
Low Frequency ◽  
Vibration Isolator ◽  
Linear Vibration ◽  
Vibration Isolators ◽  
Zero Dynamic ◽  
Low Frequency Vibration ◽  
Excited System ◽  
Better Than

Nonlinear isolators with high-static-low-dynamic-stiffness have received considerable attention in the recent literature due to their performance benefits compared to linear vibration isolators. A quasi-zero-stiffness (QZS) isolator is a particular case of this type of isolator, which has a zero dynamic stiffness at the static equilibrium position. These types of isolators can be used to achieve very low frequency vibration isolation, but a drawback is that they have purely hardening stiffness behavior. If something occurs to destroy the symmetry of the system, for example, by an additional static load being applied to the isolator during operation, or by the incorrect mass being suspended on the isolator, then the isolator behavior will change dramatically. The question is whether this will be detrimental to the performance of the isolator and this is addressed in this paper. The analysis in this paper shows that although the asymmetry will degrade the performance of the isolator compared to the perfectly tuned case, it will still perform better than the corresponding linear isolator provided that the amplitude of excitation is not too large.

Recent Study on the Passive and Active Vibration Isolators

2014 ◽  
Vol 494-495 ◽  
pp. 491-496
Author(s):  
Hua Ping Mei ◽  
Hao Yue Tian ◽  
Shuan Huang
Keyword(s):  
Vibration Isolation ◽  
Control Method ◽  
Low Frequency ◽  
Research Direction ◽  
Magnetic Suspension ◽  
High Frequency Oscillation ◽  
Future Research ◽  
Vibration Isolator ◽  
Vibration Isolators ◽  
Active Vibration

The vibration isolators have witnessed significant developments due to pressing demands for high resolution metrology and manufacturing, optical, physical and chemical experiments. In the view of these requirements, the engineers and physicists have exploited different types of vibration isolators. This paper firstly presents the recent developments on the passive vibration isolators. It finds that the passive vibration isolators can constrain the high frequency oscillation. The active control is the efficient method to cancel the low frequency vibration. Then, the paper is concerned with the recent advances on the active vibration isolator. The appropriate actuator, sensor and advanced control method are the key component of the active vibration isolator to enhance their vibration isolation properties. Finally, the author proposes that the magnetic suspension vibration isolator is a future research direction in the field of the vibration isolation.

scholarly journals An Air Spring Vibration Isolator Based on a Negative-Stiffness Structure for Vehicle Seat

2021 ◽  
Vol 11 (23) ◽  
pp. 11539
Author(s):  
Cong Hung Nguyen ◽  
Cong Minh Ho ◽  
Kyoung Kwan Ahn
Keyword(s):  
Vibration Isolation ◽  
Dynamic Stiffness ◽  
Low Frequency ◽  
Negative Stiffness ◽  
Vibration Isolator ◽  
Air Spring ◽  
Nonlinear Force ◽  
Mechanical Spring ◽  
Negative Stiffness Mechanism ◽  
Vehicle Seat

This research introduces an air spring vibration isolator system (ASVIS) based on a negative-stiffness structure (NSS) to improve the vehicle seat’s vibration isolation performance at low excitation frequencies. The main feature of the ASVIS consists of two symmetric bellows-type air springs which were designed on the basis of a negative stiffness mechanism. In addition, a crisscross structure with two straight bars was also used as the supporting legs to provide the nonlinear characteristics with NSS. Moreover, instead of using a vertical mechanical spring, a sleeve-type air spring was employed to provide positive stiffness. As a result, as the weight of the driver varies, the dynamic stiffness of the ASVIS can be easily adjusted and controlled. Next, the effects of the dimension parameters on the nonlinear force and nonlinear stiffness of ASVIS were analyzed. A design process for the ASVIS is provided based on the analytical results in order to achieve high static–low dynamic stiffness. Finally, numerical simulations were performed to evaluate the effectiveness of the ASVIS. The results obtained in this paper show that the values of the seat displacement of the ASVIS with NSS were reduced by 77.16% in comparison with those obtained with the traditional air spring isolator without NSS, which indicates that the design of the ASVIS isolator with NSS allows the effective isolation of vibrations in the low-frequency region.

scholarly journals A Novel Ring Spring Vibration Isolator for Metro Superstructure

2021 ◽  
Vol 11 (18) ◽  
pp. 8422
Author(s):  
Yuhong Ling ◽  
Shan Wu ◽  
Jingxin Gu ◽  
Hongtao Lai
Keyword(s):  
Vibration Isolation ◽  
Common Knowledge ◽  
Displacement Curve ◽  
Vibration Isolator ◽  
Spring Stiffness ◽  
Dynamic Simulations ◽  
Theoretical Derivation ◽  
Vibration Isolators ◽  
Good Energy ◽  
Compression Springs

Due to the serious impact of metro vibration on people’s lives, it is important to design vibration isolators. In this study, the dynamic characteristics of a thick-walled ring spring are studied first. Through theoretical derivation, a new formula suitable for thick-walled ring springs is proposed. Finite element numerical analysis was performed to study the load–displacement curve and stress of the ring spring and verified the correctness of the formula. According to the studied mechanic characteristics, a novel ring spring isolator is proposed for vibration isolation of the metro superstructure. With the help of a ring spring, the proposed isolator has good energy absorption and self-reset function. The dynamic simulations were conducted in a multi-story building with the ring spring isolator as the isolator to study the vibration performance. It is common knowledge that the vertical natural frequency of the superstructure that is isolated by compression springs is given by the mass of the superstructure and the spring stiffness. In order to obtain vibration attenuation and control the vertical deformation, the spring stiffness needs to be 500–1000 kN/mm. Hence, it is clear that the vibration isolator does reduce the vertical eigenfrequency. By comparing the isolated structure with the non-isolated structure, it is proved that the new isolator can effectively improve a building’s serviceability.

scholarly journals Modeling and Vibration Analysis of a 3-UPU Parallel Vibration Isolation Platform with Linear Motors Based on MS-DT-TMM

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Wei Chen ◽  
Jiaqi Tong ◽  
Hehe Yang ◽  
Fulong Liu ◽  
Zhen Qin ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Transfer Matrix ◽  
Vibration Analysis ◽  
Vibration Isolation ◽  
Vibration Suppression ◽  
Vibration Isolator ◽  
Suppression Effect ◽  
Linear Motors ◽  
Vibration Experiment ◽  
Simulation Results

The dynamics and vibration characteristics of a 3-UPU parallel mechanism isolator are investigated by theoretical modeling, numerical simulation, and experimental study. The system consists of two platforms, three linear motors, and the Hook hinges. Firstly, the dynamical mathematical model of this vibration isolator is innovatively established and solved by using the discrete-time transfer matrix method of the multibody system (MS-DT-TMM). According to the modeling principle, the transfer matrix of each component is derived, including the upper and lower platforms, Hooke hinges, and linear motors. Then, the dynamical equation of the overall system is obtained by multiplying all transfer matrices. Secondly, the solution of equation is calculated through the setting of boundary conditions. The numerical simulation is carried out according to the known parameters. The dynamical and vibration analysis of the isolation platform is performed, involving the displacement and force characteristics of the branches. Furthermore, in view of the fact that the Hooke hinges and linear motors are simplified as spatial elastic hinges in modeling. The vibration suppression effect caused by adjusting spring stiffness and damping coefficient is discussed. The simulation results verified the correctness of the MS-DT-TMM method through the comparison with ADAMS simulation results. Finally, the prototype of the vibration isolator is constructed and assembled, and the vibration experiment is conducted. By testing the responses of the isolation device mounted on the vibration table, the natural frequency of the isolator is obtained. The purpose of this experiment is to avoid resonance when it is applied as a vibration isolator in the future. This paper provides a theoretical basis for the later vibration research and control scheme design of the 3-UPU parallel vibration isolation platform.

Theoretical and Experimental Analysis of the Non-Linear Characteristics of an Air Spring With an Orifice

2011 ◽  
Author(s):  
Yasutaka Yokota ◽  
Toshihiko Asami ◽  
Tomohiko Ise ◽  
Itsuro Honda ◽  
Hiroya Sakamoto
Keyword(s):  
Vibration Isolation ◽  
Dynamic Properties ◽  
Flow Characteristics ◽  
Accurate Method ◽  
Air Spring ◽  
Damping Force ◽  
Linear Flow ◽  
Iterative Calculation ◽  
Non Linear ◽  
Amplitude Dependency

This paper proposes a simple but accurate method for calculating the dynamic properties of an air spring employing an orifice to produce a damping force. Air springs are very common in rail, automotive, and vibration isolation applications. However, because this type of air spring has non-linear flow characteristics, an accurate model is yet to be proposed. The restoring and damping forces in an air spring with an orifice damper vary with amplitude. This amplitude dependency has not been considered in previous studies. Proposed herein is a simple model for calculating the air spring constant and damping coefficient. However, iterative calculation is required due to the non-linearity of the spring. The theoretical and experimental results are found to agree well. The theoretical equations provide an effective tool for air spring design.

Theoretical and Experimental Analysis of the Nonlinear Characteristics of an Air Spring With an Orifice

2013 ◽  
Vol 135 (1) ◽  
Author(s):  
Toshihiko Asami ◽  
Yasutaka Yokota ◽  
Tomohiko Ise ◽  
Itsuro Honda ◽  
Hiroya Sakamoto
Keyword(s):  
Vibration Isolation ◽  
Dynamic Properties ◽  
Flow Characteristics ◽  
Accurate Method ◽  
The Body ◽  
Nonlinear Flow ◽  
Air Spring ◽  
Damping Force ◽  
Nonlinear Characteristics ◽  
Amplitude Dependency

We herein propose a simple but accurate method for calculating the dynamic properties of an air spring that uses an orifice to produce a damping force. Air springs are commonly used in rail, automotive, and vibration isolation applications. However, because this type of air spring has nonlinear flow characteristics, accurate approaches have not yet been proposed. The restoring and damping forces in an air spring with an orifice damper vary with the amplitude of the body. This amplitude dependency has not been considered in previous studies. We herein propose a simple model for calculating the air spring constant and damping coefficient. However, this requires iterative calculation due to the nonlinearity of the air spring. The theoretical and experimental results are found to agree well with each other. The theoretical equations provide an effective tool for air spring design.

Contrast Test Research on Application of Dry Friction Isolators to Vibration Isolation of Vehicle Electronic Devices

2014 ◽  
Vol 505-506 ◽  
pp. 360-364
Author(s):  
Jun Fang Hou ◽  
Rong Li Li ◽  
Guang Chun Yu ◽  
Tao Luo ◽  
Hai Wen He
Keyword(s):  
Dry Friction ◽  
Vibration Isolation ◽  
Electronic Device ◽  
Electronic Devices ◽  
Three Dimensional ◽  
Wire Mesh ◽  
Vibration Source ◽  
Vibration Isolator ◽  
Vibration Isolators ◽  
Research On Application

As regards the reliability of the vehicle electronic devices on the tracklayer getting worse due to severe vibration, isolation theory and mechanical model of the GWF vibration isolator and wire-mesh vibration isolator were analyzed, and the test research on the isolation effectiveness of the two isolators applied to the isolation of the vehicle electronic devices were carried out. The test results show that the vibration source of the foundation of the electronic device is mainly from the structure resonance, and the two dry friction vibration isolators exhibit excellent isolation effectiveness on different roads and at different speed. The wire-mesh vibration isolator shows better performance than GWF vibration isolator on three-dimensional comprehensive isolation.

scholarly journals Protection of precision spacecraft equipment from internal sources of vibration

2021 ◽  
Vol 5 (4) ◽  
pp. 217-226
Author(s):  
Yu. A. Zhukov ◽  
E. B. Korotkov ◽  
S. A. Matveev ◽  
N. S. Slobodzyan ◽  
O. V. Shirobokov
Keyword(s):  
Vibration Isolation ◽  
Vibration Suppression ◽  
Thermal Control ◽  
Vibration Source ◽  
Electric Pump ◽  
Pump Unit ◽  
Isolation System ◽  
Vibration Isolators ◽  
Vibration Protection ◽  
Vibration Dampers

The work is devoted to the protection of a spacecraft from the influence of unacceptable internal vibration sources. The urgency of reducing the vibration activity on board the spacecraft to improve the accuracy of the target equipment is indicated. A particular problem of vibration protection of the spacecraft platform from a vibration source – an electric pump unit of a liquid thermal control system – is being solved. The basic requirements for electric pump unit vibration protection have been determined. Possible ways to reduce the level of vibration excited by the electric pump unit on the surface of the spacecraft fixation are considered. Particular attention is paid to such vibration protection methods as damping and vibration isolation, implemented by installing special vibration protection devices between the source (electric pump unit) and the object (spacecraft) – vibration isolators and vibration dampers. The principles of operation of vibration dampers and vibration isolators, the most common materials for vibration dampers are described. Examples of constructive solutions for linear single-axial vibration isolators are considered, recommendations for the use of promising products are developed. Particularemphasis is placed on the use of metal rubber as a material for vibration isolators. With regard to a specific design of electric pump unit, a diagram of the spatial structure of vibration isolation is proposed. Formulas for calculation are given in detail, a mathematical model of the vibration isolation system is developed. The procedure for calculating the parameters of the system has been formed. Based on the model, the maximum possible level of vibration suppression in the mid-frequency region was determined. Minimum required number of operable pixels was identified for monitoring the water surface with sufficient accuracy and reliability.

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