INFLUENCE OF A TRANSVERSE MAGNETIC FIELD AND OF HYDROSTATIC PRESSURE ON THE ELASTICITY STATE OF ANISOTROPIC MAGNETORHEOLOGICAL ELASTOMERS

We manufacture an anisotropic magnetorheological elastomer (aMRE) based on silicone rubber and carbonyl iron microparticles. A plane capacitor having aMRE as dielectric material is obtained by placing the aMRE between two electroconductive disks, followed by polymerization in a transverse magnetic field. The electrical capacitance of the capacitor in the magnetic field, and respectively under mechanical compression is measured by using a new experimental setup. It is shown that in a magnetic field, the capacitance depends sensibly on the direction of application of the magnetic field intensity. Under the action of mechanical compression, the capacitance is equivalent to the one measured when the transverse magnetic field is applied. The modification of the electric capacitance is the effect of magneto-striction of aMRE in the magnetic field. We describe the observed effects by using the dipolar approximation and linear elasticity theory for small deformations.