Design and Control of a Magnetorheological Elastomer Dynamic Vibration Absorber for Powertrain Mount Systems of Automobiles

The principle of a magnetorheological elastomer (MRE) dynamic vibration absorber (DVA) is proposed and the corresponding configuration is designed in this paper. The MRE DVA is composed of a vibration absorbing unit and a passive vibration isolation unit. The vibration absorbing unit can be utilized to mitigate the kinetic energy acting on the primary system (i.e., the system of which the vibration will be mitigated) and the passive vibration isolation unit utilized to support the primary system. The vibration absorbing unit consists of magnetic conductor, shearing sleeve, bobbin core, electromagnetic coil winding, and vulcanized MRE between the shearing sleeve and the bobbin core. The magnetic field produced by the electromagnetic coil winding starts from the bobbin core, and passes through the magnetic conductor and the shearing sleeve, then goes through the MRE and forms a closed loop. The shear storage modulus of the MRE could be tuned continuously by varying the applied current, which results in natural frequency shift of the MRE DVA. The optimal parameters of the electromagnetic circuit of the MRE DVA are calculated based on Kirchoff’s law. The finite element method is employed to validate the electromagnetic circuit of the MRE DVA and to obtain the corresponding electromagnetic characteristics. The mathematical model of the MRE DVA is also derived. In order to analyze how the parameters of the MRE DVA influence the effectiveness of the vibration control and to validate the flexibility of the control systems, the MRE DVA is employed in a powertrain mount system to replace the conventional passive mount. A single-degree-of-freedom (SDOF) dynamic model for the semi-active powertrain mount system is established. A varied step optimum algorithm is adopted to realize the vibration control of the powertrain mount system based on the MRE DVA.