Analysis of a semi-active MR-damper with hysteretic and asymmetric properties

A generalized model is proposed to characterize the hysteretic damping properties of a magneto-rheological (MR) fluid damper, which yield asymmetric force in compression and rebound. The proposed nonlinear damper model incorporating applied current, and magnitude and frequency of the response, is employed within a two-DOF "quarter-car" model to evaluate the dynamic response characteristics of the semi-actively controlled MR-damper. The "skyhook" control law is employed to realize variable damping of the hysteretic and asymmetric damper. The simulation results are presented to demonstrate the contributions due to damping asymmetry and hysteresis on the responses. The results of the study suggest that the controller synthesis can be greatly simplified using the proposed damper model.