Viscoelastic plastic continuous physical model of a magnetorheological damper applied in the high speed train

In the preliminary design stage of high-speed train smart suspension, a simple, yet accurate magnetorheological (MR) damper model whose parameters have clear physical meaning is needed. Based on the working mechanism analysis and the dynamic behavior study of the MR damper, a new consecutive viscoelastic plastics (VEP) model is proposed. A methodology to find the parameters of the proposed model directly has been proposed. The comparison with experimental results indicates that the proposed model could adequately characterize the intrinsic nonlinear behavior of the MR damper, including the hysteretic behavior, roll-off phenomenon, and the variation of the hysteresis width in terms of the frequency and magnitude of excitation. The results of experimental testing prove that the accuracy of the proposed model is higher than that of the phenomenological model while only containing four undetermined parameters with clear physical meaning. Moreover, based on the proposed VEP model, a nonlinear stiffness VEP (nkVEP) model is developed with higher precision in the hysteretic region. The nkVEP model, which can reproduce the behavior of the damper with fluctuating input current, is developed. The proposed model could predict accurately the response of the MR damper in a wide range of frequency and displacement.