Modeling and Analyzing of Hysteresis Behavior of Magneto Rheological Dampers

AbstractDamping force-velocity hysteresis of a magnetorheological (MR) damper under sinusoidal displacement excitation is not only a typical indication of its dynamic performance, but also the foundation upon which a practical control strategy is established. Although numerous parametric and non-parametric models are effectively in predicting the hysteresis, their accuracy strongly depends on specific experimental data. Furthermore, little design guiding information can be explored from these models. With compressibility of MR fluid considered, ordinary differential equations (ODEs) of a physical MR damper model are derived in this paper. Then the corresponding lumped parameter model is developed, that is, a quasi-static MR model connected in series with a spring expressing compression of MR fluid. Moreover, the spring stiff expression is found to be equivalent to the “oil spring” in hydraulic technology. Decomposing a quasi-static MR model further to a friction element and a parallel-connected viscous element, these two basic elements in combination with a spring together fundamentally constitute a dynamic MR damper model. Consequently, a clear developing process of the hysteresis can be described with these three basic elements. As another main contribution of this paper, expression for calculating hysteresis width is derived by neglecting viscous element, and dynamic design method of MR dampers is proposed