Magnetorheological (MR) materials are classified as smart materials due to their responsiveness to external magnetic stimuli. Intensive research on MR materials has led to broad applications in several potential fields. A solid carrier matrix state called MR elastomer with its exceptional magnetic responsive feature is obtained by merging magnetizable particles within an elastomeric polymer. This integration results in outstanding characteristics on the rheological performances. Special prominence is given to the understanding of the base materials and fabrication as well as the functional behavior through various characterization methods. Broad applications of MREs are also explored to provide a profound market picture and to motivate researchers to develop novel technology. The functional behavior of MREs is briefly explained. The art of the materials provides the current position and mapping of the matrix and filler particles. Types of matrix and particles are mentioned together with the level of the research interest on MREs. Description of the fabrication is provided in simple diagrams as summarized from previous works to enhance the MREs performance. The possible tests to reveal the characteristics of the MREs are delivered with the global experimental setup. The review also explains the applications of MREs as well as discussion on the MREs future promising applications.

Recent Progress on Magnetorheological Solids: Materials, Fabrication, Testing, and Applications†

Magneto-active elastomers are smart materials composed of a rubber-like matrix material containing a distribution of magneto active particles. The large elastic deformations possible in the rubber-like matrix allow the mechanical properties of magneto-active elastomers to be changed significantly by the application of external magnetic fields. In this paper, we provide a theoretical basis for the description of the nonlinear properties of a particular class of these materials, namely transversely isotropic magneto-active elastomers. The transversely isotropic character of these materials is produced by the application of a magnetic field during the curing process, when the magneto active particles are distributed within the rubber. As a result the particles are aligned in chains that generated a preferred direction in the material. Available experimental data suggest that this enhances the stiffness of the material in the presence of an external magnetic field by comparison with the situation in which no external field is applied during curing, which leads to an essentially random (isotropic) distribution of particles. Herein, we develop a general form of the constitutive law for such magnetoelastic solids. This is then used in the solution of two simple problems involving homogeneous deformations, namely simple shear of a slab and simple tension of a cylinder. Using these results and the experimental available data we develop a prototype constitutive equation, which is used in order to solve two boundary-value problems involving non-homogeneous deformations—the extension and inflation of a circular cylindrical tube and the extension and torsion of a solid circular cylinder.

Transversely isotropic nonlinear magneto-active elastomers

Magnetostrictive polymer composites: Recent advances in materials, structures and properties

This article presents a novel model to portray the behavior of magnetorheological elastomer in oscillatory shear test. The dynamic behavior of an isotropic magnetorheological elastomer is experimen...

A new approach for modeling of magnetorheological elastomers

This paper presents a procedure for manufacturing composites, a methodology for testing them and the cyclic properties of isotropic magnetorheological elastomers. The choice of a thermoplastic matrix and magnetically active iron powder as the filling (much larger than the carbonyl iron powder filling used so far) is expounded. A manufacturing technology has been developed. Possibilities for the experimental investigation of magnetomechanical properties have been created by building a measuring system enabling the testing of various elastomers in a wide range of mechanical and magnetic parameters. The effect of the magnetic field and that of the stress frequency on the damping properties of a selected elastomer (considered to be optimal) were examined.

https://iopscience.iop.org/article/10.1088/0964-1726/19/4/045014/pdf

Isotropic magnetorheological elastomers with thermoplastic matrices: structure, damping properties and testing

Amplitude and frequency dependence of magneto-sensitive rubber in a wide frequency range

A nonlinear constitutive audio frequency magneto-sensitive rubber model including amplitude, frequency and magnetic field dependence

The frequency, amplitude and magnetic field dependent torsional stiffness of a magneto-sensitive rubber bushing

In a noise reduction context, magneto-sensitive (MS) rubber is likely to become a reality in the very near future This conclusion is reached from the following: a review of the rapidly growing literature on the subject, a discussion around experimentally obtained data on magneto-sensitive rubber, and finally a computer simulation of a MS rubber isolator which seeks to illustrate the utility and great potential of this smart material within the audible frequency range In contrast to normal rubber, magneto-sensitive rubber contains small iron particles that respond to externally applied magnetic fields, consequently altering the mechanical properties of the rubber This response increases for small strains strengthening further the link to structure-borne sound applications where displacement amplitudes are usually small; this is borne out by vibration measurements in a running car engine, included for the purpose of placing experimental data on MS rubber in a real context

Magneto-sensitive rubber in a noise reduction context – exploring the potential

A magneto-sensitive rubber isolator inserted between a source and an infinite plate is modelled in the audible frequency range, and the energy flow into the plate with the rubber subjected to a magnetic field applied perpendicular to the axial displacement is calculated. Subsequently the result is compared to the corresponding energy flow for zero magnetic induction; upon the application of an external magnetic field the rubber becomes stiffer, thus shifting the internal resonances of the isolator. This is a fast and reversible process enabling adaption of the isolator to rapidly changing audio frequency conditions by simply turning on and off a magnetic field. In the application example considered, the energy flow into the plate at the first internal dynamic peak stiffness frequency is reduced by approximately 7 dB—a large difference in a sound and vibration context—by inducing magnetic saturation of the rubber.

http://iopscience.iop.org/article/10.1088/0964-1726/17/1/015043/pdf

Peter Blom

Papers

Amplitude and frequency dependence of magneto-sensitive rubber in a wide frequency range

A nonlinear constitutive audio frequency magneto-sensitive rubber model including amplitude, frequency and magnetic field dependence

The frequency, amplitude and magnetic field dependent torsional stiffness of a magneto-sensitive rubber bushing

Magneto-sensitive rubber in a noise reduction context – exploring the potential

Smart audio frequency energy flow control by magneto-sensitive rubber isolators