A novel magnetorheological elastomer isolator with negative changing stiffness for vibration reduction (original) (raw)
Related papers
Development and Dynamic Characterization of a Mixed Mode Magnetorheological Elastomer Isolator
IEEE Transactions on Magnetics, 2017
Magnetorheological elastomers (MREs) are a kind of smart material, whose mechanical properties are controllable with applied magnetic field. Moreover, there is a greater magnetorheological effect for MREs at small strain amplitude, which has attracted more attention in the field of microvibration control. In this paper, an MRE isolator with shear-compression mixed mode was developed to suppress the high-frequency and microamplitude vibration of a precision-fabrication platform. To evaluate and characterize the dynamic behavior of the MRE isolator, experiments were conducted under harmonic load and different magnetic fields, respectively. Experiments showed that the resonance frequency of the MRE isolation system shifted from 45.82 (0 A) to 82.55 Hz (1.5 A). Meanwhile, the relative change in equivalent stiffness and damping was 175% and 216%, respectively, and the relative change in isolator force was 190% from 0 to 1.5 A. The proposed mixed mode MRE isolator effectively isolated vibration at high frequency for microamplitude.
Magnetorheological Elastomer Stiffness Control for Tunable Vibration Isolator
Proceeding of the Electrical Engineering Computer Science and Informatics
Most of the vibration isolator has fixed stiffness such as a passive vehicle mounting system. Objective of this research is to develop a Magneto-rheological Elastomer (MRE) as a vibration isolator; stiffness of vibration absorber can be controlled by an applied magnetic field. An MRE was fabricated by mixing silicon rubber, silicon oil and carbonyl iron particles together and then cured for 24 hours in a circular mold. The experimental result shows the absorption capacity of the developed MRE is better than the traditional MRE in time and frequency domains.
Development of Vibration Isolator Using Magnetorheological Elastomer Material Based
Journal of Applied Engineering Science
Many vibration isolators, for instance, passive vehicle mounting device, have fixed stiffness. This article presents the development of the adjustable stiffness engine mounting magnetorheological elastomers (MREs) based to reduce vibration. The development of MREs vibration isolator is to design of engine mounting first step, for next step is to simulate the electromagnetic circuit. The housing material selection and MREs thickness were considered to equip sufficient, uniform magnetic fields to change the stiffness. The innovative magnetic circuit design includes the type and size of the wire and the number of the coil turns to obtain the best magnetic fields to eliminate vibration. Finite Element Method Magnetics (FEMM) software was utilized to show the effectiveness of the electromagnetic circuit in generating magnetic fields through the MREs. Finally, various current input influence to the MREs vibration isolator is investigated. The higher current input is more useful to elimina...
Modeling of a new semi-active/passive magnetorheological elastomer isolator
Smart Materials and Structures, 2014
This paper presents theoretical modeling of a new magnetorheological elastomer (MRE) base isolator and its performance for vibration control. The elastomeric element of the traditional steel-rubber base isolator is modified to a composite layer of passive elastomer and MRE which makes the isolator controllable with respect to its stiffness and damping. The proposed variable stiffness and damping isolator (VSDI) is designed based on an optimized magnetic field passing through MRE layers to achieve maximum changes in mechanical properties. The controllability of the VSDI is investigated experimentally under double lap shear tests. A model employing the Bouc-Wen hysteresis element is proposed to characterize the force-displacement relationship of the VSDI. An integrated system which consists of four VSDIs is designed, built and tested. Dynamic testing on the integrated system is performed to investigate the effectiveness of the VSDIs for vibration control. Experimental results show significant shift in natural frequency, when VSDIs are activated and the possibility of using the VSDIs as a controllable base isolator.
Dynamic Properties of Magnetorheologic Elastomer
Rakenteiden Mekaniikka, 2007
SUMMARY Machinery and buildings often have to be protected from vibrations. The needed reduction of dynamic response can be achieved efficiently with semi-active isolation. One way to use semi-active isolation is to install vibration isolators between the base and the object to be protected and control the dynamic properties of these isolators. The advantage of semiactive isolation compared to passive isolation is the adjustability of the system. With adaptive semi-active isolators it is possible to react simultaneously to the changes of the loads and dynamics of the system. This paper describes the laboratory tests and the measurement results of an improved vibration isolator material and an improved adaptive vibration isolator developed by the Technical Research Centre of Finland (VTT). On the basis of the results the presented adaptive material and isolator system is applicable for typical industrial and transportation environments.
Characterization of Magneto-Rheological Elastomer and Modelling of MRE Based Isolators
2018
Magneto rheological elastomer (MRE) is a new kind of smart material whose dynamic properties can be altered in the real time with an externally applied magnetic field. This advantage of MRE has brought up its application to the development of real time adaptable base isolation systems, with ability to change the stiffness and damping according to applied magnetic field. The MRE base isolator generally consist of a laminated layer of MR elastomer sheets and steel sheets, sandwiched between two thick steel plates one at top and other at bottom, and enclosed by a current carrying coil. Current in the coil generates magnetic field which alter the stiffness and damping of the isolator and by controlling the current, the required stiffness and damping can be achieved. In this study, characterization and modelling of the current dependent visco-elastic properties of synthetic rubber based MRE is carried out. Synthetic rubber based MRE were fabricated with magneto-sensitive carbonyl iron (C...
IEEE Access, 2021
Longitudinal vibrations due to different external excitations are omnipresent in almost every machine, eventually leading to unplanned downtime, and in some cases, catastrophic failures. The passive approach to isolate such vibration has some limitations. Magnetorheological elastomers (MREs) typically consist of micron-sized ferrous particles dispersed in an elastomeric matrix. Its rheological properties, such as the viscosity and dynamic modulus, can be altered when subjected to a magnetic field. Thus, magnetorheological elastomers have drawn significant attention from researchers due to their versatility in vibration control applications. In this study, an MRE-based metamaterial coupler is fabricated for broadband vibration attenuation. The vibration control performance of the proposed model is investigated in terms of its transmissibility factor. Sine sweep vibration testing is used to examine the transmissibility factor for single, double, and triple-layer MRE metamaterial couplers accompanied by different activation scenarios. The results reveal that the stiffness of the MRE layers increases with the strength of the applied magnetic field. Utilizing more than one layer of MRE increases the ability to isolate longitudinal vibration at different frequency bands. The maximum reduction curves achieved by single, double, and triple-layer MREs are approximately 84.5%, 97%, and 99.6%, respectively. The findings of this study demonstrate that the proposed MRE-based metamaterial couplers can attenuate vibrations at broadband frequencies.
Magnetorheological Elastomer-Based Variable Stiffness Flexible Coupling for Vibration Isolation
Transactions of the Canadian Society for Mechanical Engineering, 2021
Magnetorheological elastomers (MRE) are smart composite materials by which their mechanical properties, such as stiffness, are changed under a magnetic field. In this article, the introduction of a variable stiffness coupling (VSC) fitted within a shaft for torsional vibration isolation that would adapt and change its attenuation frequency range is presented. The VSC concept on torsional vibration isolation is tested experimentally. MRE samples with 40% volume fraction are fabricated and manufactured using a 3D mold design and fixed within a coupling in a shaft to investigate the magnetic field effect on the torsional rigidity. Impact hammer test is conducted along with an accelerometer to obtain the transmissibility factor analysis. Results show that the vibration level decreases when the magnetic field increases. The 1st natural frequency of the system happened at 26 Hz and moved to 28 Hz when the applied current increases from 0 mT to 12.38 mT. MRE torsional stiffness increased f...
Mechanical Sciences
The semi-active torsional vibration absorber can effectively reduce the torsional vibration of the power-train system. In this paper, a new type of variable stiffness torsional vibration absorber with a magnetorheological elastomer (MRE) as an intelligent controlling element is designed, and the modal analysis, frequencytracking scheme, and damping effects have been studied. A transient dynamic simulation is utilized to validate the rationality of the mechanical structure, the magnetic field parameters of the absorber are matched, and the magnetic circuit simulation analysis and the magnetic field supply analysis are carried out to verify the closed magnetic circuit. The principle prototype of the innovative vibration absorber is manufactured, the magnetic field strength of the absorber is tested by a Gauss meter, and the results show the efficacy of magnetizing the vibration absorber with a conductive slip ring by solving the magnetizing problem of the rotating parts of the vibration absorber. A special-purpose test rig with a torsional vibration exciter as a power source has been implemented. A comparative experiment has been carried out to test the frequency shift characteristics and authenticate the vibration-reduction effect of the new MRE torsional vibration absorber.