Behavior of thick magnetorheological elastomers

In this study, the behavior of thick magnetorheological elastomers is experimentally investigated. Two types of magnetorheological elastomer specimens of varying concentrations, with circular and rectangular shapes having thicknesses from 6.35 mm to a maximum of 25.4 mm, are prepared. The magnetorheological elastomer samples are studied under quasi-static compression and double lap-shear tests. The shear and the Young's moduli of the magnetorheological elastomers are obtained under different applied magnetic fields. It is observed that the field-induced change in the modulus is independent of the thickness of the magnetorheological elastomer and is only dependent on the iron particle concentration and the magnetic field strength. With the increase in the applied magnetic field, it is observed that the change in modulus varies from a linear behavior at lower applied magnetic fields to a nonlinear one at higher magnetic fields. It is found that compressive and shear moduli only depend on the applied magnetic fields and are independent of the sample thickness. In addition, the maximum induced change in material modulus under compression is shown to be 99%, whereas in shear it is found to be 68% when compared to its off-state.