Study on the Application of Magnetorheological Damper in Chaotic Vibration Control

2007 ◽  
Author(s):  
Shuyong Liu ◽  
Shijian Zhu ◽  
Xiang Yu ◽  
Jingjing Wang
Keyword(s):  
Nonlinear Vibration ◽  
Vibration Isolation ◽  
Harmonic Excitation ◽  
Magnetorheological Damper ◽  
Single Frequency ◽  
Control Line ◽  
Chaotic State ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Chaotic Vibration

The nonlinear vibration isolation system works in a chaotic state when its parameters are in chaotic range. Under single frequency harmonic excitation, the output of this system is broad spectrum response, and thus the chaotic vibration isolation system is applied to control line spectra of the warship water-born noise. The passive vibration isolation system, however, cannot change the parameters when the work condition of isolated equipments is varied, and it is difficult to ensure that the system is in chaotic state. In order to adjust the system parameter on line, the magnetorheological damper can be used to control chaos in nonlinear vibration isolation systems. The system model with magnetorheological damper is presented in this paper, and then the simulation is carried out. Results show that the magnetorheological damper can be used to reduce the amplitude of the chaotic vibration when voltage is applied to the MR. When the voltage is increased, the system can exhibit period behaviour. This is a new method for chaos control.

Vibration Isolation and Chaotic Vibration

2003 ◽  
Author(s):  
Rong-Jun Jiang ◽  
Shi-Jian Zhu
Keyword(s):  
Nonlinear Vibration ◽  
Vibration Isolation ◽  
Harmonic Excitation ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Chaotic Vibration ◽  
Vibration State ◽  
Vibration Isolation Performance ◽  
Isolation Performance ◽  
Better Than

Taking single degree of freedom vibration isolation system under simple harmonic excitation as an example, and considering the energy, the vibration isolation performance in different conditions was studied theoretically and numerically. The results shows that when the simple harmonic excitation import energy is definite, the vibration isolation performance at the primary harmonic frequency of the nonlinear vibration isolation system is better than that of the linear system, and the vibration isolation performance of the nonlinear vibration isolation system in chaotic vibration state is much better than that in non-chaotic vibration state. For the same isolated object, if can let the vibration isolation system vibrate chaotically, the system will possess the best isolation performance at the primary frequency.

Numerical Study on the Application of Chaos in Line Spectrum Reduction

2009 ◽  
Author(s):  
Jingjun Lou ◽  
Shijian Zhu
Keyword(s):  
Power Flow ◽  
Vibration Isolation ◽  
Numerical Study ◽  
Excitation Amplitude ◽  
Point Of View ◽  
Line Spectrum ◽  
Chaotic State ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Two Degree Of Freedom

The application of chaos method in line spectrum reduction is numerically studied. The nonlinear dynamics and the power flow transmissibility of a two-degree-of-freedom vibration isolation system with nonlinear spring are analyzed. The dynamic behavior distribution chart of the system is obtained. Cascades of bifurcation of the system with different excitation amplitude are also gained. The isolation effectiveness is analyzed from the point of view of energy. The numerical results show that the reduction of the line spectrum in chaotic state is much greater than that in non-chaotic state.

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.

Modeling and Verification of an Innovative Active Pneumatic Vibration Isolation System

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
H. Porumamilla ◽  
A. G. Kelkar ◽  
J. M. Vogel
Keyword(s):  
Natural Frequency ◽  
Vibration Isolation ◽  
Computational Study ◽  
Hydraulic Cylinder ◽  
Magnetorheological Damper ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Seat Suspension ◽  
Active Vibration ◽  
Novel Concept

This paper presents a novel concept in active pneumatic vibration isolation. The novelty in the concept is in utilizing an air-spring-orifice-accumulator combination to vary the natural frequency as well as inject damping into the system per requirement, thereby eliminating the need for a hydraulic cylinder or a magnetorheological damper. This continuously variable natural frequency and damping (CVNFD) technology is aimed at achieving active vibration isolation. For analysis purposes, a particular application in the form of pneumatic seat suspension for off-road vehicles is chosen. A mathematical model representing the system is derived rigorously from inertial dynamics and first principles in thermodynamics. Empirical corelations are also used to include nonlinearities such as friction that cannot be accounted for in the thermodynamic equations. An exhaustive computational study is undertaken to help understand the physics of the system. The computational study clearly depicts the CVNFD capability of the vibration isolation system. An experimental test rig is built to experimentally validate analytical and simulation modeling of the system. Experimental verification corroborated the variable natural frequency and damping characteristic of the system observed through computational simulations.

A Study of Chaotic Motion on Non-Linear Vibration-Isolation System

2001 ◽  
Author(s):  
Qing Ouyang ◽  
Shi-Jian Zhu ◽  
Yin Shi
Keyword(s):  
Frequency Band ◽  
Chaotic Motion ◽  
Vibration Isolation ◽  
Physical Parameters ◽  
Linear Vibration ◽  
Chaotic State ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Broad Frequency Band ◽  
Non Linear

Abstract This paper deals with the vibration isolation efficiency of non-linear vibration-isolation system in a desired chaotic state. Numerical calculation shows that the response of a non-linear vibration system might have broad frequency band characterization, even though the excitation is a harmonic one if some physical parameters of the system is in certain value regimes, hence the force transferred to the supporting foundation from the isolated body will be a broad frequency band one. The practical experimental set was designed. In order to control the system in a desired chaotic state, the isolator must be a non-linear one with variable stiffness and damping. The chaotic motion of the system was identified through phase space reconstruction and spectral analysis based on the measured test data. The result shows that it is feasible to decrease the single line spectrum component significantly in the response by means of controlling chaotic vibration.

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.

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