Test setup for examination of magneto-mechanical properties of magnetorheological elastomers with use of a novel approach (original) (raw)

Experimental Analysis of Magneto-Rheological Elastomer

2016

Recently, a very attractive and effective semiactive absorbers featuring magneto-rheological (MR) materials such as MR fluids (MRFs) or MR elastomers (MRE’s) have been proposed by many investigators. These absorbing devices based on MR technique have a number of attractive characteristics for use in vibration control, such as fast response characteristic to magnetic field, wide control bandwidth and compact size. MR materials include MRFs, MR foams and MREs, whose rheological properties can be controlled by the application of an external magnetic field. The most common MR material is MRFs, which is magnetically polarizable particles suspended in viscous fluids. Since their invention in 1948, MRF technique has made significant advancements. The MRFs have been proved to be commercially viable and well suited for many applications, such as the automotive suspension vibration control, the earthquake resistance, clutch. Solid analogs of MRFs and MREs can avoid those disadvantages such as...

Development and Characterization of Isotropic Magnetorheological Elastomer

Universal Journal of Mechanical Engineering, 2013

Magneto rheological elastomer (MRE) is a new kind of smart materials. Its dynamic mechanical performances can be controlled by controlling an applied magnetic field. MRE is usually used as stiffness-changeable spring in the semi-active vibration absorber. In order to get perfect vibration control effect, low dynamic damping of MRE is needed. This paper presents a new method of fabricating isotropic MREs under normal temperature and pressure conditions. In the absence of a magnetic field, a variety of MR elastomer samples were prepared using Sylard's184 silicone elastomer along with un-annealed electrolytic iron power 500 mesh and 15 micron size. Their dynamic characteristics like fractional change in resonant frequency and fractional change in have been studied. The effects of iron particles and the applied magnetic field were investigated. This study is also expected to provide a good guide for designing and preparing new MR elastomers.

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.

Fabrication and Response Analysis of Magnetorheological Elastomer

Material Science Research India, 2012

Smart materials are materials with properties that can be significantly altered in a controlled fashion by external stimuli, such as stress, temperature, pH, moisture, electric or magnetic fields. An elastomer comprising a matrix interspersed with micron sized ferromagnetic particles is known as a Magnetorheological Elastomer (MRE). The rheological properties of MREs are altered by the application of an external magnetic field. The characteristic response of MRE is influenced by many factors including; the elastomer matrix, the size, distribution, composition and percentage volume of the ferromagnetic particles, and whether the ferromagnetic particles are aligned in chains or randomly dispersed. During the past two decades the interest in intelligent material based solutions has shown a huge growth. Present work deals with the study of preparation method of Magnetorheological Elastomer mould and testing for its dynamic behaviour. Micron size iron particles are used for the preparati...

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...

Response Analysis of Isotropic and Anisotropic Magnetorheological Elastomer

The purpose of this paper is to research the response of isotropic and anisotropic Magnetorheological Elastomer (MRE) with 15 and 30 percent of iron particles comprising in matrix of MRE with respect to transmissibility and percentage of vibration absorption. Fabrication and experimental investigation were carried out to study the response of MREs with respect to transmissibility and percentage of vibration absorption by using fast fourier transform (FFT). To ensure the validation of experimental result different readings were taken to compare characteristics in different loading conditions. Result obtained from the experimental analysis of samples of isotropic and anisotropic MREs with with 15 and 30 percent of iron particles were compared. Result show that best performance of vibration control and transmissibility were obtained with fabrication of anisotropic and isotropic MRE with 30 gm iron particle behind that anisotropic and isotropic MRE with 15 gm iron particle have good results of vibration control.

Magnetorheological Elastomers: A Review

Applied Mechanics and Materials, 2014

This present paper reviews on the material compositions of Magnetorheological elastomer (MRE) as presented by researchers. As the article review, this paper much focuses on the selection of the material in the MRE ingredients. MRE has been known as a new kind of smart material over past decades. MREs offer innovative solutions for various applications in the engineering field since the rheological properties of MREs can be controlled by an external magnetic field. The characteristic responses of MRE are influenced by many factors such its elastomer matrix, the size, distribution, composition, percentage volume of filler particles and so on.

Role of Magnetorheological Fluids and Elastomers in Today’s World

Acta Mechanica et Automatica

This paper explains the role of magnetorheological fluids and elastomers in today’s world. A review of applications of magnetorheological fluids and elastomers in devices and machines is presented. Magnetorheological fluids and elastomers belong to the smart materials family. Properties of magnetorheological fluids and elastomers can be controlled by a magnetic field. Compared with magnetorheological fluids, magnetorheological elastomers overcome the problems accompanying applications of MR fluids, such as sedimentation, sealing issues and environmental contamination. Magnetorheological fluids and elastomers, due to their ability of dampening vibrations in the presence of a controlled magnetic field, have great potential present and future applications in transport. Magnetorheological fluids are used e.g. dampers, shock absorbers, clutches and brakes. Magnetorheological dampers and magnetorheological shock absorbers are applied e.g. in damping control, in the operation of buildings ...

Study of magnetorheology and sensing capabilities of MR elastomers

Journal of Physics: Conference Series, 2013

This study focuses on the magnetorheology and sensing capability of graphite based Magnetorheological Elastomers (Gr MREs). By introducing graphite (Gr) to conventional MREs, the Gr MREs are derived. The anisotropic sample with 20% graphite weight fraction was selected to be compared with anisotropic conventional MREs. The microstructures of anisotropic Gr MREs and conventional MREs were observed. Both steady state tests and dynamic tests were conducted to study rheological properties of the samples. For dynamic tests, the effects of strain amplitude, and frequency on both storage modulus and loss modulus were measured. For sensing capability, the resistance of selected Gr MREs under different magnetic fields and external loadings is measured with a multi-meter. Either higher magnetic field or more external loading results in the resistance increment. Based on an ideal assumption of perfect chain structure, a mathematical model was proposed to investigate the relationship between the MRE resistance with the external loadings. In this model, the current flowing through the chain structure consists of both tunnel current and conductivity current, both of which depends on external loadings. The modelling parameters were identified and reconstructed from comparison with experimental results. The comparison indicates that both experimental results and modelling prediction agree favourably well.

Homopolymer Based Magnetorheological Elastomer

International Journal of Scientific Research in Science, Engineering and Technology, 2020

Magnetorheological rubber belongs to the class of ‘Smart Material’ whose mechanical properties can be altered continuously and reversibly by an applied magnetic field. Magnetorheological rubber (MRE’s) are composites that consists of magnetically polarisable particles mixed into rubber matrix. With suitable controlled algorithms, they respond to change in their environment. Purpose of this work is to know more about magnetorheological rubber for active stiffness, vibration control and dampening applications. Although few applications of these materials have been reported in the literature, the possibilities are numerous. They can be used for various applications such as vibration absorber, vibration isolator, variable stiffness bush, spring, force sensors, actuators etc.