DESIGN AND ANALYSIS OF A MAGNETORHEOLOGICAL FLUID MOUNT FEATURING UNI-DIRECTIONAL SQUEEZE MODE

A magnetorheological fluid (MRF) mount featuring unidirectional squeeze mode for vehicle engine mounting system is proposed and designed to attenuate the engine vibration with characteristics of broadband and small amplitude. The MRF mount is comprised of upper and lower bases for installation, a main rubber for static load, a bobbin for electromagnetic coil winding and a squeeze plate. The bottom surface of the bobbin and the top surface of the squeeze plate form the polar plates, between which the MRF is squeezed during the rebound of the MRF mount. Combining dynamic stiffness property of passive hydraulic mounts without fluid and adjustable damping force of MRF at squeeze mode, the MRF mount could provide a unique variable dynamic stiffness and damping properties, by adjusting the exciting current. To evaluate the performance of the MRF mount, a mathematical model considering the behavior of MRF at squeeze mode is derived to theoretically analyze and numerically simulate the dynamic stiffness and equivalent damping properties of the MRF mount. Further, the MRF mount based quarter vehicle mounting system model considering suspension system is constructed to analyze the force transmissibility of engine mounting system in frequency domain and simulate the relative displacement response in time domain.