Modeling of a new semi-active/passive magnetorheological elastomer isolator (original) (raw)
Related papers
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.
Modeling of a new magnetorheological elastomer-based isolator
Active and Passive Smart Structures and Integrated Systems 2013, 2013
A variable stiffness and damping isolator (VSDI) is designed and developed employing MREs. A double lap shear test has been carried out to characterize two MRE based VSDIs under quasi-static shear loading. A phenomenological model which can capture the behavior of the VSDI is developed and related parameters are identified using experimental data. Both experimental and theoretical modeling results have shown good agreements.
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...
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.
Smart Materials and Structures, 2014
Magneto-rheological elastomers (MREs) have attracted notable credits in the development of smart isolators and absorbers due to their controllable stiffness and damping properties. For the purpose of mitigating unwanted structural and/or machinery vibrations, the traditional MRE-based isolators have been generally proven effective because the MR effect can increase the stiffness when the magnetic field is strengthened. This study presents a novel MRE isolator that experienced reduced stiffness when the applied current was increased. This innovative work was accomplished by applying a hybrid magnet (electromagnet and permanent magnets) onto a multilayered MRE structure. To characterise this negative changing stiffness concept, a multilayered MRE isolator with a hybrid magnet was first designed, fabricated and then tested to measure its properties. An obvious reduction of the effective stiffness and natural frequency of the proposed MRE isolator occurred when the current was continuously adjusted. This device could also work as a conventional MRE isolator as its effective stiffness and natural frequency also increased when a negative current was applied. Further testing was carried out on a one-degree-of-freedom system to assess how effectively this device could isolate vibration. In this experiment, two cases were considered; in each case, the vibration of the primary system was obviously attenuated under ON-OFF control logic, thus demonstrating the feasibility of this novel design as an alternative adaptive vibration 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.
Vibration Control of Magnetorheological Elastomer Beam Sandwich
Proceeding of the Electrical Engineering Computer Science and Informatics
A Magnetorheological Elastomer (MRE) is a smart material and that could change their properties by exposure to stimuli such as electric and magnetic fields, stress moisture and temperature. The objective of this research is to develop an MRE as a vibration isolator of a beam sandwich under different currents to get different stiffness of the MRE. 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 that there were decreases in amplitude of the vibration in time and frequency domains when the current applied to the coil is increased.
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...
A new isolator for vibration control
2011
This study presents the feasibility of a new variable stiffness and damping isolator (VSDI) in an integrated vibratory system. The integrated system comprised of two VSDIs, a connecting plate and a mass. The proposed VSDI consists of a traditional steel-rubber vibration absorber, as the passive element, and a magneto-rheological elastomer (MRE), with a controllable (or variable) stiffness and damping, as the semi-active element. MREs' stiffness and damping properties can be altered by a magnetic field. Dynamic testing on this integrated system has been performed to investigate the effectiveness of the VSDIs for vibration control. Experimental results show significant shift in natural frequency, when activating the VSDIs. Transmissibility and natural frequency of the integrated system are obtained from properties of single device. The experimental and predicted results show good agreement between the values of the natural frequency of the system at both off and on states. However, system damping predictions are different from experimental results. This might be due to unforeseen effects of pre-stressed MREs and nonlinear material properties.
A new isolator for vibration control
Active and Passive Smart Structures and Integrated Systems 2011, 2011
This study presents the feasibility of a new variable stiffness and damping isolator (VSDI) in an integrated vibratory system. The integrated system comprised of two VSDIs, a connecting plate and a mass. The proposed VSDI consists of a traditional steel-rubber vibration absorber, as the passive element, and a magneto-rheological elastomer (MRE), with a controllable (or variable) stiffness and damping, as the semi-active element. MREs' stiffness and damping properties can be altered by a magnetic field. Dynamic testing on this integrated system has been performed to investigate the effectiveness of the VSDIs for vibration control. Experimental results show significant shift in natural frequency, when activating the VSDIs. Transmissibility and natural frequency of the integrated system are obtained from properties of single device. The experimental and predicted results show good agreement between the values of the natural frequency of the system at both off and on states. However, system damping predictions are different from experimental results. This might be due to unforeseen effects of pre-stressed MREs and nonlinear material properties.