Magnetorheological isolators using multiple fluid modes

This study presents the experimental and theoretical evaluation of an MR (magnetorheological) isolator using multiple fluid modes including shear, flow and squeeze. For doing so, a novel type of multi-mode MR isolator against multi-degree-of-freedom excitations is proposed and fabricated. The experimental testing of the proposed MR isolator is conducted by an MTS machine and its damper characteristics are experimentally evaluated by equivalent damping and complex stiffness methods. To construct a theoretical model of the MR isolator, its dynamic equation is derived and important model parameters are identified by the force averaging method using the force-displacement or the force-velocity plots. Using the theoretical model, the damper characteristics of the MR isolator are also predicted and compared to those computed using the experimental data.