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.

Dynamic Analysis of Nonlinear Vibration Isolation System Based on Flexible Foundation

2014 ◽  
Vol 1030-1032 ◽  
pp. 766-769
Author(s):  
Shu Ying Li ◽  
Rui Huo ◽  
Xing Ke Cui ◽  
Cui Ping Liu ◽  
Dao Kun Zhang
Keyword(s):  
Nonlinear Vibration ◽  
Power Flow ◽  
Vibration Isolation ◽  
Low Frequency ◽  
Coupled System ◽  
Optimized Design ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Vibration Isolators ◽  
Flexible Foundation

In this paper,a general dynamic model of the isolation coupled system which is composed of isolation object,nonlinear vibration isolation support,and flexible foundation is established,calculated method of applying vibration power flow to analyze isolation effectiveness is studied.Further more,as an calculation example,a air spring vibration isolation system of HS-700 engines is numerically simulated.Designs several low-frequency nonlinear vibration isolators and analyzes its vibration isolation effect.It discusses the effect of the vibration isolator parameters on the transmitted power flow of the system.The results provide a theoretical basis for the optimized design of nonlinear vibration isolation system.

Dynamic Analysis of Multi-Supported Nonlinear Vibration Isolation System Mounted on Flexible Foundation

2013 ◽  
Vol 419 ◽  
pp. 223-227 ◽  
Author(s):  
Rui Huo ◽  
Hui Yu ◽  
Yan Feng Guan
Keyword(s):  
Numerical Solution ◽  
Nonlinear Vibration ◽  
Power Flow ◽  
Vibration Isolation ◽  
Engineering Application ◽  
System Dynamic ◽  
Dynamic Equations ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Flexible Foundation

In view of its prototype in engineering application, a theoretical model of multi-supported nonlinear vibration isolation system installed on flexible foundation is studied, including derivation of system dynamic equations and analysis of system dynamic characteristics. For effectiveness evaluation of nonlinear vibration isolation systems, a generalized time-averaged power is proposed as an extension of classical theory of vibratory power flow, and a numerical solution method of time-averaged power is probed accompanying with the numerical solution of nonlinear dynamic equations. In a further concrete calculation example, an air spring vibration isolation system of a small UAV engine is numerically simulated based on Runge-Kutta method, and dynamic behavior and power flow transmission characteristics influenced by system parameters are investigated.

scholarly journals Dynamic Modeling and Characteristic Analysis of Floating Raft System with Attached Pipes

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Longlong Ren ◽  
Yang Li ◽  
Xiuchang Huang ◽  
Hongxing Hua
Keyword(s):  
Power Flow ◽  
Vibration Isolation ◽  
Transmission Performance ◽  
Characteristic Analysis ◽  
Vibration Transmission ◽  
Floating Raft ◽  
Flow Through ◽  
The Mean ◽  
Vibration Isolation Performance ◽  
Isolation Performance

The vibration transmission performance of a floating raft system with attached pipes is investigated in this paper. The frequency response function-based (FRF-based) substructure synthesizing method whose accuracy has been verified by numerical simulations and experiment is applied for modeling the system. The power flow through the transmission paths is used for exploring the additional vibration transmission path provided by the attached pipes. The results show that the existence of the additional transmission paths caused by the pipes breaks the symmetries of the system, which leads to the enhancement of the coupling between each substructure. Consequently, it degrades the vibration isolation performance of the raft system. Moreover, a parametric study is performed to investigate the effects on the mean-square velocity of the hull of the attached pipes, which gives a brief guideline for designing the attached pipes.

Acoustic decoupling for structural elements by affixed supports - inherent contradiction or perfect complement? Restrained vibration isolation supports - a critical review

2021 ◽  
Vol 263 (4) ◽  
pp. 2801-2811
Author(s):  
Adam Wells ◽  
Patrick Carels
Keyword(s):  
Analytical Model ◽  
Critical Review ◽  
Laboratory Testing ◽  
Vibration Isolation ◽  
Mechanical Vibration ◽  
Structural Elements ◽  
Noise And Vibration ◽  
Vibration Isolators ◽  
Models Comparison ◽  
Isolation Performance

Restrained vibration isolation supports balance efficient isolation performance and stability for the supporting body under present loads. Necessary and beneficially for noise and vibration isolation applications with stringent stability requirements, such as full building isolation with potential uplift, interior partition sway bracing, curtain walls, elevator rail isolation, and mechanical vibration isolation, the performance of restrained vibration isolators are often misunderstood or oversimplified. This paper investigates the general vibration isolation theory used to create the analytical model for restrained isolation supports, intricacies of vibration isolation materials which may cause reality to diverge from well-known models, comparison of theory to laboratory testing, and a review of common uses/applications for these types of vibration isolation solutions, and recommendation to avoid undesired results from common pitfalls associated with restrained isolation supports implementation and installations.

Bio-Inspired Vibration Isolation: Methodology and Design

2021 ◽  
Vol 73 (2) ◽  
Author(s):  
Ge Yan ◽  
Hong-Xiang Zou ◽  
Sen Wang ◽  
Lin-Chuan Zhao ◽  
Zhi-Yuan Wu ◽  
...  
Keyword(s):  
Vibration Isolation ◽  
Variable Stiffness ◽  
Practical Applications ◽  
Vibration Isolators ◽  
Ultralow Frequency ◽  
Vibration Isolation Performance ◽  
Isolation Performance ◽  
Control Accuracy ◽  
Isolation Mechanisms ◽  
Auxiliary Mass

Abstract Various bio-inspired vibration isolators have been emerged in recent decades and applied successfully in the protection of sensitive components, improvement of operating comfort, enhancement of control accuracy, etc. They are generally developed by exploiting favorable nonlinearities in biological structures. The main contribution of this work is to provide a comprehensive review of recent studies on the bio-inspired isolators. The methodology of bio-inspired vibration isolation is proposed from the perspective of mechanics based on the elemental theory and design principles. The key isolation mechanisms are classified into three categories according to different dominant forces: stiffness adjustment mechanism, auxiliary mass mechanism, and damping mechanism, respectively. Some representative designs, performance analyses, and practical applications of each type of bio-inspired isolators are also provided. In bio-inspired isolators with variable stiffness, the inherent structural performances can be adjusted to deal with variation in external load. The auxiliary mass mechanism utilizes nonlinear inertial effects to achieve ultralow frequency vibration isolation. Unique damping mechanism of bio-inspired structures is often studied to protect devices and equipment from impact loads. Bio-inspired vibration methods can also be applied in active/semi-active control systems with advantages of low energy consumption and high robustness. Finally, the review ends with conclusions, which highlight resolved and unresolved issues and provide a brief outlook on future perspectives. This review aims to give a comprehensive understanding of bio-inspired isolation mechanism. It also provides guidance on designing new bio-inspired isolators for improving their vibration isolation performance.

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.

Research on Comprehensive Control of Vibration Isolation System with Flexible Foundation

2011 ◽  
Vol 55-57 ◽  
pp. 872-876
Author(s):  
De Zhen Feng ◽  
Fang Zhou ◽  
Zai Mei Zhang ◽  
Hua Guan Liu
Keyword(s):  
Power Flow ◽  
Vibration Isolation ◽  
Passive Control ◽  
Positive Control ◽  
Matrix Analysis ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Practical Engineering ◽  
Flexible Foundation ◽  
Vibrational Power Flow

The paper analyzes the dynamic relation of asymmetric multi-supported vibration isolation system with flexible foundation, establishes the comprehensive model of passive control and positive control system by using the effective matrix analysis method, analyzes the transmission mechanism and characteristic of vibrational power flow in the flexible vibration isolation system. In order to meet the need of the practical engineering, the paper analyzes and calculates the effect of the machine mass on the input and the transmission power flow in detail. At last, the paper puts forward the measure to reduce vibration energy transmission.

scholarly journals Power Flow in a Two-Stage Nonlinear Vibration Isolation System with High-Static-Low-Dynamic Stiffness

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Ze-Qi Lu ◽  
Dong Shao ◽  
Hu Ding ◽  
Li-Qun Chen
Keyword(s):  
Nonlinear Vibration ◽  
Power Flow ◽  
Vibration Isolation ◽  
Dynamic Stiffness ◽  
Harmonic Balance Method ◽  
Harmonic Excitation ◽  
Resonant Peak ◽  
Nonlinear Stiffness ◽  
Two Stage ◽  
Force Transmissibility

The manuscript concerns the power flow characterization in a two-stage nonlinear vibration isolator comprising three springs, which are configured so that each stage of the system has a high-static-low-dynamic stiffness. To demonstrate the distinction of evaluation for vibration isolation using power flow, force transmissibility is used for comparison. The dynamic behavior of the isolator subject to harmonic excitation, however, is of interest here. The harmonic balance method (HBM) could be used to analyze the frequency response curve (FRC) of the strong nonlinear vibration system. A suggested stability analysis to distinguish the stable and the unstable HBM solutions is described. Increasing both upper and lower nonlinear stiffness could bend the first resonant peak to the left. The isolation range in the power and the force transmissibility plot could be extended to the lower frequencies when the nonlinear stiffness is increased, but the rate of roll-off for the power transmissibility is twice the rate for the force transmissibility at each horizontal stiffness setting. An explanation for this phenomenon is given in the paper.

The effect of side-restraint bearings on the performance of base-isolated buildings

2003 ◽  
Vol 217 (8) ◽  
pp. 849-859 ◽  
Author(s):  
J P Talbot ◽  
H E M Hunt
Keyword(s):  
Vibration Isolation ◽  
Base Isolation ◽  
Vertical Direction ◽  
Vertical Motion ◽  
Urban Road ◽  
Common Solution ◽  
Generic Models ◽  
Isolation Frequency ◽  
Flexible Foundation ◽  
Isolation Performance

Base-isolation of buildings is a common solution to the problem of ground-borne vibration from urban road and rail networks. Conventional designs incorporate vibration isolation bearings between a building and its foundation, aligned in the vertical direction so as to isolate the building from vertical motion of its foundation. In some cases, in order to accommodate horizontal loads, additional side-restraint bearings aligned in the horizontal direction are required. This paper describes a theoretical investigation into the effect of side-restraint bearings on the performance of base-isolated buildings. Three generic models, based on a modern concrete-framed building, are used to demonstrate that a building's flexibility, the nature of the vibration input and the presence of a flexible foundation are all important in determining isolation performance. It is also illustrated how the concept of isolation frequency, commonly used to indirectly specify the stiffness of base bearings, may not be generally extended to side-restraint bearings. The models indicate that, for maximum performance, the stiffness of any side-restraint bearings should be minimized.

Application of a dynamic antiresonant vibration isolator to minimize the vibration transmission in underwater vehicles

2017 ◽  
Vol 24 (17) ◽  
pp. 3819-3829 ◽  
Author(s):  
Niuniu Liu ◽  
Chenyang Li ◽  
Caiyu Yin ◽  
Xingjian Dong ◽  
Hongxing Hua
Keyword(s):  
Power Flow ◽  
Thrust Bearing ◽  
Vibration Mode ◽  
Underwater Vehicle ◽  
Vibration Isolator ◽  
Harmonic Force ◽  
Vibration Transmission ◽  
Force Transmissibility ◽  
Isolation Performance ◽  
Analytical Dynamic

Harmonic axial force resulting from a propeller’s first vibration mode is a major cause of tonal sound radiation of an underwater vehicle. To reduce the harmonic force, we employ a dynamic antiresonant vibration isolator (DAVI) in parallel with thrust bearing of the shafting system to attenuate vibration transmitted to the hull. The methods of transfer matrices and substructure synthesis are used to create a semi-analytical dynamic model of the propeller–shaft–hull system with DAVI. In this model, the elastic properties of the propeller and foundation are taken into consideration. The force transmissibility and power flow are then used to evaluate the isolation performance of the DAVI. For the purpose of comparison, a resonance changer (RC) proposed in the published literature is also used to reduce the axial vibration transmission. It is demonstrated numerically that by using DAVI, the vibration and power flow of the underwater vehicle are greatly attenuated at the designed frequency without obviously changing the axial fundamental resonance frequency of the shafting system, which is superior to the RC isolator.

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