Shear properties of a magnetorheological elastomer

Abstract

This paper presents an experiment testing the damped free vibration of a systemcomposed of a magnetorheological elastomer and a mass. The goal of thisexperiment was to obtain the dependence of the natural frequency and thedamping ratio of the structure on the applied magnetic field. The shearproperties, including the shear storage modulus and the damping factor, weretherefore determined. The experimental results revealed that the shear storagemodulus could reach a value of 60% of the zero-field modulus and was dominatedby the magnetic field, but the change in the damping factor could be neglected.Furthermore, when the field was moderate and saturation did not occur, the shearstorage modulus increased proportionally with the applied field. This interestingphenomenon was analysed, and it is suggested that the subquadratic fielddependence, which arises from the saturation of the magnetization near thepoles of closely spaced pairs of spheres, must be taken into consideration.