Modelling the hysteretic characteristics of a magnetorheological fluid damper

Abstract

A generalized model is proposed to characterize the biviscous hysteretic force characteristics of a magnetorheological (MR) fluid damper using symmetric and asymmetric sigmoid functions on the basis of a fundamental force generation mechanism, observed qualitative trends and measured data under a wide range of control and excitation conditions. Extensive laboratory measurements were performed to characterize the hysteretic force properties of an MR damper under a wide range of magnitudes of control current and excitation conditions (frequency and stroke). The global model is realized upon formulation and integration of component functions describing the preyield hysteresis, saturated hysteresis loop, linear rise and current-induced rise. The validity of the proposed model is demonstrated by comparing the simulation results with measured data in terms of hysteretic forcedisplacement and force-velocity characteristics under a wide range of test conditions. The results revealed reasonably good agreement between the measured data and model results, irrespective of the test conditions considered. The results of the study suggest that the proposed model could be effectively applied for characterizing the damper hysteresis and for development of an optimal controller for implementation in vehicular suspension applications.