Magnetorheological Isolators Using Multiple Fluid Modes

Abstract

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.

Keywords

magnetorheological fluids magnetorheological isolator equivalent damping complex stiffness shear mode flow mode squeeze mode.

Get full access to this article

View all access options for this article.

References

Choi, S.B. and Choi, Y.T. 1999. ``Sliding Mode Control of Shear-mode Type ER Engine Mount,'' KSME International Journal, 13(1):26—33.

Choi, S.B. , Choi, Y.T. , Cheong, C.C. and Jeon, Y.S. 1999. ``Performance Evaluation of a Mixed Mode ER Engine Mount Via Hardware-in-the-loop Simulation,'' Journal of Intelligent Material Systems and Structures, 10(8):671—677.

Choi, Y.T. and Wereley, N.M. 2004. ``Quasi-steady Analysis of a Magnetorheological Dashpot Damper,'' ASME International Mechanical Engineering Congress and Expo, Anaheim, California, November 13—19, IMECE2004-52378.

Jolly, M.R. and Carlson, J.D. 1996. ``Controllable Squeeze Damping Using Magnetorheological Fluid,'' 5th International Conference on New Actuators , pp. 333—336.

Lindler, J. and Wereley, N.M. 1999. ``Analysis and Testing of Electrorheological Bypass Dampers ,'' Journal of Intelligent Material Systems and Structures , 10(5):363—376.

Lou, Z. , Ervin, R.D. , Filisko, F.E. and Winkler, C.B. 1993. ``An Electrorheologically Controlled Semi-active Landing Gear,'' SAE Technical Paper Series 931403.

Wereley, N.M. and Pang, L. 1998. ``Nondimensional Analysis of Semi-active Electrorheological and Magnetorheological Dampers Using Approximate Parallel Plate Models,'' Smart Materials and Structures, 7(5):732—743.