Design of a stiffness variable flexible coupling using magnetorheological elastomer for torsional vibration reduction

In this study, the design of an magnetorheological elastomer flexible coupling whose torsional stiffness can be controlled by an embedded magnetic field generator is proposed. It is designed to minimize the torsional vibration transmission between shafts adaptively to the dynamic disturbance. The coupling insert is composed of magnetorheological elastomer which is a smart material whose stiffness can be controlled by an external magnetic field. This article also proposes a compact magnetic field generator which can be fitted inside the coupling hubs, to control the torsional stiffness of the magnetorheological elastomer. The finite element method was used to design and estimate the dynamic stiffness variation of the magnetorheological elastomer coupling due to the applied magnetic field and disturbance frequency. Also, torsional vibration experiments were conducted to validate the performance of the proposed magnetorheological elastomer coupling. Results showed that it can adaptively tune in a range of frequencies between 16.8 and 23.5 Hz and has 95.7% stiffness variation under magnetic field of 150mT. The proposed system is expected to achieve a higher MRE effect with a softer base matrix.