Semi-Active Isolation System Using Self-Powered Magnetorheological Dampers

2009 ◽  
Author(s):  
Young-Tai Choi ◽  
Hyun Jeong Song ◽  
Norman M. Wereley
Keyword(s):  
Vibration Isolation ◽  
Mr Damper ◽  
The Self ◽  
Isolation System ◽  
Power Harvesting ◽  
Seat Suspension ◽  
Active Isolation ◽  
Self Powered ◽  
Vibration Isolation Performance ◽  
Isolation Performance

This study addresses experimental evaluation of a semi-active vibration isolation system using a self-powered magnetorheological (MR) damper. To this end, a self-powered MR damper was constructed by electronically connecting an MR damper with a power harvesting dynamic vibration absorber (DVA) that can convert mechanical energy due to vibration and shock into electrical energy by means of electromagnetic induction. In this study, an MR damper for seat suspensions of the Expeditionary Fighting Vehicle (EFV) was chosen for the application of the self-powered MR damper. The generated voltage, current, and power of the power harvesting DVA were experimentally measured in frequency domain under various acceleration levels of 0.3–1.2 g (where one g = 9.81 m/s2). In addition, damper force testing of the self-powered MR damper (i.e., in this study, a prototype EFV MR damper with the power harvesting DVA) was experimentally conducted in time and frequency domains. To evaluate vibration isolation performance of a semi-active isolation system using the self-powered MR damper, an EFV seat suspension mockup using the self-powered MR damper was constructed. Under eight different representative random excitation accelerations, the vibration isolation performance of the EFV seat suspension mockup using the self-powered MR damper was experimentally evaluated.

Self-Powered Magnetorheological Dampers

Aerospace ◽  
2006 ◽  
Author(s):  
Young-Tai Choi ◽  
Norman M. Wereley
Keyword(s):  
Energy Harvesting ◽  
Vibration Isolation ◽  
Mr Damper ◽  
The Self ◽  
Dynamic Vibration Absorber ◽  
Time Domains ◽  
Self Powered ◽  
Optimal Stiffness ◽  
Vibration Isolation Performance ◽  
Isolation Performance

This paper addresses the feasibility and effectiveness of a self-powered magnetorheological (MR) damper operated by the energy harvested from vibration and shock environment. For doing so, an energy-harvesting device is theoretically constructed and added to an MR damper. This energy-harvesting device consists of a stator, a permanent magnet and a spring, and works as an energy-harvesting dynamic vibration absorber (DVA). The dynamic equation for the self-powered MR damper is derived theoretically. In order to theoretically evaluate the vibration isolation capability of the self-powered MR damper, a single-degree-of-freedom engine mounting system using the MR damper is constructed. The governing equation of motion for the engine mounting system is theoretically derived. A parametric study is conducted to find the optimal stiffness of the energy-harvesting DVA for the engine mounting system. Under various excitation displacements and a shock load, the vibration isolation performance of the engine mounting system with the self-powered MR damper is theoretically evaluated in frequency and time domains.

Self-Powered Magnetorheological Dampers

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Young-Tai Choi ◽  
Norman M. Wereley
Keyword(s):  
Energy Harvesting ◽  
Vibration Isolation ◽  
Mr Damper ◽  
The Self ◽  
Dynamic Vibration Absorber ◽  
Engine Mount ◽  
Self Powered ◽  
Optimal Stiffness ◽  
Isolation Performance

This study addresses the feasibility and effectiveness of a self-powered magnetorheological (MR) damper using in-situ energy harvested from the vibration and shock environment in which it is deployed. To achieve this, an energy-harvesting device is designed and added to a MR damper. This energy-harvesting device consists of a stator, a permanent magnet, and a spring and operates as an energy-harvesting dynamic vibration absorber (DVA). The dynamic equation for the self-powered MR damper is derived. To evaluate the vibration isolation capability of the self-powered MR damper, a single-degree-of-freedom engine mount system using the MR damper is simulated. The governing equation of motion for the engine mount system is derived. A parametric study is conducted to find the optimal stiffness of the energy-harvesting DVA for the engine mount system. The isolation performance of the engine mount system employing the self-powered MR damper is theoretically evaluated in the frequency domain.

scholarly journals Experimental Validation of Fly-Wheel Passive Launch and On-Orbit Vibration Isolation System by Using a Superelastic SMA Mesh Washer Isolator

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Seong-Cheol Kwon ◽  
Mun-Shin Jo ◽  
Hyun-Ung Oh
Keyword(s):  
Vibration Isolation ◽  
Application Form ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Static Tests ◽  
Resolution Observation ◽  
Passive Vibration Isolation ◽  
Basic Characteristics ◽  
Vibration Isolation Performance ◽  
Isolation Performance

On-board appendages with mechanical moving parts for satellites produce undesirable micro-jitters during their on-orbit operation. These micro-jitters may seriously affect the image quality from high-resolution observation satellites. A new application form of a passive vibration isolation system was proposed and investigated using a pseudoelastic SMA mesh washer. This system guarantees vibration isolation performance in a launch environment while effectively isolating the micro-disturbances from the on-orbit operation of jitter source. The main feature of the isolator proposed in this study is the use of a ring-type mesh washer as the main axis to support the micro-jitter source. This feature contrasts with conventional applications of the mesh washers where vibration damping is effective only in the thickness direction of the mesh washer. In this study, the basic characteristics of the SMA mesh washer isolator in each axis were measured in static tests. The effectiveness of the design for the new application form of the SMA mesh washer proposed in this study was demonstrated through both launch environment vibration test at qualification level and micro-jitter measurement test which corresponds to on-orbit condition.

scholarly journals High-Efficiency Vibration Isolation for a Three-Phase Power Transformer by a Quasi-Zero-Stiffness Isolator

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Hao Cao ◽  
Yaopeng Chang ◽  
Jiaxi Zhou ◽  
Xuhui Zhao ◽  
Ling Lu ◽  
...  
Keyword(s):  
Vibration Isolation ◽  
High Efficiency ◽  
Power Transformer ◽  
Dynamic Stiffness ◽  
Harmonic Balance Method ◽  
Isolation System ◽  
Three Phase ◽  
Engineering Practices ◽  
Vibration Isolation Performance ◽  
Isolation Performance

The vibrations generated by a three-phase power transformer reduce the comfort of residents and the service life of surrounding equipment. To resolve this tough issue, a quasi-zero-stiffness (QZS) isolator for the transformer is proposed. This paper is devoted to developing a QZS isolator in a simple way for engineering practices. The vertical springs are used to support the heavy weight of the transformer, while the oblique springs are employed to fulfill negative stiffness to neutralize the positive stiffness of the vertical spring. Hence, a combination of the vertical and oblique spring can yield high static but low dynamic stiffness, and the vibration isolation efficiency can be improved substantially. The dynamic analysis for the QZS vibration isolation system is conducted by the harmonic balance method, and the vibration isolation performance is estimated. Finally, the prototype of the QZS isolator is manufactured, and then the vibration isolation performance is tested comparing with the linear isolator under real power loading conditions. The experimental results show that the QZS isolator prominently outperforms the existing linear isolator. This is the first time to devise a QZS isolator for three-phase power transformers with heavy payloads in engineering practices.

Vibration Isolation of Precision Payloads for Aerial Vehicles Using Magnetorheological Isolators

2005 ◽  
Author(s):  
Young-Tai Choi ◽  
Mikel Brigley ◽  
Norman M. Wereley
Keyword(s):  
Vibration Isolation ◽  
Control Input ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Aerial Vehicles ◽  
Lqg Control ◽  
Field Control ◽  
Aerial Vehicle ◽  
Vibration Isolation Performance ◽  
Isolation Performance

This study addresses the application of MR (magnetorheological) isolators to vibration isolation of precision payloads for aerial vehicles. To this end, a precision payload in an aerial vehicle is modeled as a six-degree-of-freedom (DOF) lumped parameter model of a sensor assembly. An MR isolator is modeled as a 3-DOF passive spring-damping element and a 3-DOF semi-active yield force due to the yield stress of an MR fluid. Three MR isolators are configured with equal installation angles between the precision payload and the base structure in the aerial vehicle. The governing equations of motion for the MR vibration isolation system of the precision payload for the aerial vehicle are derived and then key parameters of the MR isolators, such as stiffness, damping, and isolator orientation, are determined via a global optimization method. The simulated response of the passive MR vibration isolation system with no magnetic field control input and constant magnetic field control input are presented and analyzed under different excitation conditions. To improve the passive MR vibration isolation performance, a linear quadratic Gaussian (LQG) control algorithm is designed. Finally, simulated responses of the semi-active MR vibration isolation performance using LQG control are evaluated and compared with those of passive (zero or constant field) MR vibration isolation systems.

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.

scholarly journals Dynamics and control of a bio-inspired Stewart platform

2021 ◽  
Vol 39 (2) ◽  
pp. 258-266
Author(s):  
Yuansheng Peng ◽  
Honghua Dai ◽  
Hao Zhang ◽  
Xiaokui Yue
Keyword(s):  
Dynamic Model ◽  
Feedback Linearization ◽  
Vibration Isolation ◽  
Control Method ◽  
Stewart Platform ◽  
The Novel ◽  
Isolation System ◽  
Theoretical Simulation ◽  
Vibration Isolation Performance ◽  
Isolation Performance

Collision and strong impacts take place in mission of the on orbit capture of non-cooperative spacecraft. So, it is necessary to design a vibration isolation system with efficient vibration isolation performance. A Stewart vibration isolation platform based on the bio-inspired isolation system is proposed in this paper. The characteristics of the novel bio-inspired Stewart platform realizes the vibration isolation protection of the serving spacecraft during the capture mission. The dynamic model of the vibration isolation platform is established by Lagrange's equations. The fidelity of the established dynamic model is verified via a comparison of the theoretical simulation and the ADAMS simulation. Comparisons between the presently proposed vibration isolation platform and the traditional spring-mass-damper type Stewart vibration isolation platform demonstrates the advantages of the present platform. The effects of system parameters on the isolation performance of the present platform are thoroughly investigated. The feedback linearization control method is used to control the present platform which overcomes the drift motion that occurs in the passive isolation case. The results show that the novel bio-inspired Stewart platform has excellent vibration isolation performance, which provides a promising way for the vibration isolation of the non-orbit capture mission.

scholarly journals Theoretical Modeling and Vibration Isolation Performance Analysis of a Seat Suspension System Based on a Negative Stiffness Structure

2021 ◽  
Vol 11 (15) ◽  
pp. 6928
Author(s):  
Xin Liao ◽  
Ning Zhang ◽  
Xiaofei Du ◽  
Wanjie Zhang
Keyword(s):  
Vibration Isolation ◽  
Vibration Suppression ◽  
Ride Comfort ◽  
Dynamic Stiffness ◽  
Suspension System ◽  
Negative Stiffness ◽  
Nonlinear Dynamic Model ◽  
Seat Suspension ◽  
Vibration Isolation Performance ◽  
Isolation Performance

In this study, to improve the vibration isolation performance of a cab seat and the ride comfort of the driver, we propose a mathematical model for a seat suspension system of a construction machinery cab based on a negative stiffness structure (NSS). First, a static analysis of a seat suspension system is conducted and the different parameters and their influences on the dynamic stiffness are discussed. Thereby, the ideal configuration parameter range of the suspension system is obtained. Moreover, the nonlinear dynamic model of the designed seat suspension system is established. The frequency response and the stability are analyzed by using the HBM method and numerical simulation. The vibration transmissibility characteristics and vibration suppression effects of the seat suspension system are presented in detail. The results show that, as compared with a quasi-zero-stiffness system, the QZS-IE system has higher vibration suppression advantages under large excitation and small damping, as well as lower transmissibility and a wider vibration isolation frequency range. In addition, an inerter element with a larger mass ratio and relatively shorter distance ratio is better for vibration isolation performance of the QZS-IE system in a practical engineering application. The results of this study provide a scientific basis for the design and improvement of a seat suspension system.

scholarly journals Shock response of a two-stage vibration isolation system

2020 ◽  
Vol 21 (2) ◽  
pp. 1-11
Author(s):  
Diego Francisco Ledezma Ramirez ◽  
Pablo Ernesto Tapia Gonzalez ◽  
Martín Castillo Morales ◽  
Tania Paloma Berber Solano ◽  
Adriana Salas Zamarripa
Keyword(s):  
Vibration Isolation ◽  
Two Stage ◽  
Isolation System ◽  
Short Pulses ◽  
Vibration Isolation System ◽  
Secondary Stage ◽  
Shock Response ◽  
Vibration Isolation Performance ◽  
Two Degree Of Freedom ◽  
Isolation Performance

Abstract. Two-degree of freedom system, or two-stage mount are used to improve the high frequency vibration isolation performance with the disadvantage of increasing the mass of the system and adding a second resonance. The vibration isolation property is a well-understood topic for harmonic vibration considering linear and nonlinear elements, but not its shock response. The absolute and relative response of a two-stage mount under shock excitation is investigated in this paper. Analysing the effect of the mass ratio between the two-stage, and its respective viscous damping. The potential advantages and issues behind this system are discussed and compared with the single mount. Experimental validation was performed using two commercial isolator and different masses. Findings suggested that a large secondary mass could reduce the shock response in terms of absolute motion. This effect is only significant for the case of short pulses and when the added mass is at least five times greater than the main mass. Being useful to have light damping only on the secondary stage.

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