Performance of natural rubber and silicone-based magnetorheological elastomers under large-strain combined axial and shear loading

This study presents an experimental investigation on large-strain behavior of natural rubber– and silicone-based magnetorheological elastomers within a larger scope of structural vibration mitigation due to wind, traffic and seismic events. Magnetorheological elastomer samples with different weight percentages of iron particles, additives, and elastomer matrix were fabricated. The microstructures of specimens were examined, and their mechanical properties were investigated by a unique electromagnetic double-lap shear experimental setup capable of applying simultaneous compression and shear loads. The experimental results demonstrated that the isotropic natural rubber–based magnetorheological elastomers exhibit about 30% magnetorheological effect under large strains, while they achieve a higher magnetorheological effect under the combined axial and shear loading. The magnetorheological effect was 92% and 33% for 10% and 100% shear strains when 100 psi axial stress was applied. A natural rubber–based magnetorheological elastomer was further investigated applying dynamic cyclic load with and without compression load for different strains, frequencies, and magnetic field intensities. It was observed that for higher frequency, magnetorheological effect was reduced. Magnetorheological effects were 73% and 29% for 0.1 and 10 Hz frequencies, respectively, under 100 psi axial stress at 150% shear strain. The result of this study suggests that isotropic natural rubber–based magnetorheological elastomers may be suitable for high-demand-force applications, and in particular, in civil structures.