Bench for the study of static and dynamic indicators of vibration isolators

2020 ◽  
pp. 36-40
Author(s):  
P.V. Sirotin ◽  
I.YU. Lebedinskiy ◽  
M.M. Jileykin ◽  
M.I. Syisoev
Keyword(s):  
Vibration Isolation ◽  
Test Bench ◽  
Operating Conditions ◽  
Technological Equipment ◽  
Vibration Isolator ◽  
Vibration Isolators ◽  
Vibration Protection ◽  
Dynamic Indicators

A test bench is developed to evaluate the properties of vibration mounts intended for vibration isolation of units, assemblies and workplaces of vehicle operators and technological equipment. The estimation of static and dynamic indicators of vibration isolators under loading close to operating conditions is presented. Keywords vibration isolator, vibration protection, vibration mount stiffness, damping, bench. [email protected]

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 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.

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.

scholarly journals Vibration Protection of Sensitive Components of Infrared Equipment in Harsh Environments

2001 ◽  
Vol 8 (1) ◽  
pp. 55-69 ◽  
Author(s):  
A.M. Veprik ◽  
V.I. Babitsky ◽  
N. Pundak ◽  
S.V. Riabzev
Keyword(s):  
Vibration Isolation ◽  
Harsh Environments ◽  
Line Of Sight ◽  
Infrared Sensor ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Vibration Isolators ◽  
Vibration Protection ◽  
Electro Optic ◽  
Environmental Vibration

This article addresses the principles of optimal vibration protection of the internal sensitive components of infrared equipment from harsh environmental vibration. The authors have developed an approach to the design of external vibration isolators with properties to minimise the vibration-induced line-of-sight jitter which is caused by the relative deflection of the infrared sensor and the optic system, subject to strict constraints on the allowable sway space of the entire electro-optic package. In this approach, the package itself is used as the first-level vibration isolation stage relative to the internal highly responsive components.It was predicted analytically, and confirmed experimentally, that the proposed vibration isolation system would be capable of a sixfold reduction of the dynamic response of the infrared sensor as compared to the case of rigid mounting of the entire package.

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.

scholarly journals A New Approach to Achieve Variable Negative Stiffness by Using an Electromagnetic Asymmetric Tooth Structure

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Chao Han ◽  
Xueguang Liu ◽  
Muyun Wu ◽  
Weilong Liang
Keyword(s):  
Vibration Isolation ◽  
Excitation Frequency ◽  
Negative Stiffness ◽  
Vibration Isolator ◽  
Linear Vibration ◽  
Excellent Performance ◽  
New Approach ◽  
Tooth Structure ◽  
Vibration Isolators ◽  
Electromagnetic Vibration

Traditional passive nonlinear isolators have been paid much attention in recent literatures due to their excellent performance compared to linear vibration isolators. However, they are incapable of dealing with varying conditions such as changing excitation frequency due to the nonadjustable negative stiffness. To solve this drawback, a new approach to achieve variable negative stiffness is proposed in this paper. The negative stiffness is realized by an electromagnetic asymmetric magnetic tooth structure and can be changed by adjusting the magnitude of the input direct current. Analytical model of the electromagnetic force is built and simulations of magnetic field are conducted to validate the negative stiffness. Then the EATS is applied to vibration isolation and an electromagnetic vibration isolator is designed. Finally, a series of tests are conducted to measure the negative stiffness experimentally and confirm the effect of the EATS in vibration isolation.

Vibration isolation of a symmetric and asymmetric rigid bar using struts subject to axial static and dynamic excitation

2010 ◽  
Vol 225 (2) ◽  
pp. 334-346 ◽  
Author(s):  
A E El-Kafrawy ◽  
A Kandil ◽  
A Omar
Keyword(s):  
Vibration Isolation ◽  
Harmonic Excitation ◽  
Vibration Isolator ◽  
Vibration Isolators ◽  
Section Modulus ◽  
Design Charts ◽  
At Resonance ◽  
Resonance Frequencies ◽  
Wide Range ◽  
Harmful Effects

Many developed modern machineries such as compressors, engines, and presses represent a serious source of undesirable, uncomfortable, and uncontrollable vibrations leading to harmful failure and loss of machine availability. Therefore, research of mechanical engineers in maintenance sections in the industry has been devoted to the control, isolation, and minimi-zation of harmful effects of such vibrations. The objective of the present paper is to study the influence of using a specific type of vibration isolator based on using post-buckled elastic clamped—clamped struts as an effective solution tool to relieve vibrating machines from these harmful effects. A model that consists of post-buckled struts acting as vibration isolators used to support symmetric and asymmetric rigid bars is introduced. The proposed clamped—clamped struts are subject to axial harmonic excitation at the base. The isolated bar is allowed to displace laterally. Displacement transmissibility is selected as the governing optimization variable of the isolator's effectiveness with the main objective to minimize vibrations transmitted from the base to the rigid bar. The transmissibility is calculated over a wide range of frequencies and plotted in the form of design charts to determine its effect on the vibration behaviour of struts. The lateral motion of the bar is considered. These plots are used to recognize the range of frequencies, for which full isolation is maintained. The frequencies at which resonance occurs in the system can then be depicted from the design graphs. The study reveals that at resonance frequencies, the most effective transmissibility is well below unity. Vibration characteristics are determined at specific frequencies, such that the physical performance of the vibrating system can be studied. All variables used in the analysis are normalized, such that the results are not dependent on any geometric of material property, such as the modulus of elasticity of the material, the section modulus of the profile used, or the length of the strut. In this way, the obtained results can be applied over a wide range of elastic materials, regardless of the type of material or section properties.

Analysis and Comparison of the Dynamic Performance of One-Stage Inerter-Based and Linear Vibration Isolators

2018 ◽  
Vol 10 (01) ◽  
pp. 1850005 ◽  
Author(s):  
Yong Wang ◽  
Ruo-Chen Wang ◽  
Hao-Dong Meng
Keyword(s):  
Vibration Isolation ◽  
Fixed Point Theory ◽  
Structural Parameters ◽  
Vibration Isolator ◽  
Linear Vibration ◽  
Isolation System ◽  
Vibration Isolators ◽  
One Stage ◽  
Performance Indexes ◽  
Isolation Performance

Inerter, which is defined as a two-terminal mechanical element, has the characteristic that the force generated at its two terminals is proportional to the relative acceleration between its two ends. Here, the inerter is used in the vibration isolation system; eight kinds of one-stage inerter-based vibration isolators are presented in this paper. Dynamic equations of eight kinds of one-stage inerter-based vibration isolators are established, the natural frequency is considered, and the dynamic response and transmissibility are obtained using the time domain analysis method or the Laplace-transformed method. Four performance indexes are defined to evaluate their isolation performance and compared with the linear vibration isolator (LVI). The best structural parameters of these one-stage inerter-based vibration isolators are determined using the H[Formula: see text] optimization method based on the fixed-point theory, which aims to minimize the maximum transmissibility. The results show that compared with the LVI, some kinds of one-stage inerter-based vibration isolators can offer a better isolation performance according to the four performance indexes. Furthermore, the best vibration isolator among these vibration isolators is determined by the four performance indexes.

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