Controllable Vibration Damper Using Magnetorheological Fluid.

Magnetorheological (MR) fluid is a functional material that responds to an applied magnetic field with a change in rheological behavior. The essential characteristic of this fluid is its ability to reversibly change from free-flowing, linear viscous liquid to semi-solid, which has controllable yield strength in milliseconds when exposed to a magnetic field. The MR fluid can, therefore, play an important role in the controllable vibration damper. In this paper, based on the experimental data, an improved mechanical model for MR damper is developed and confirmed by one degree of freedom vibration system. The model consists of a hysteresis part and a variable viscous damper proportional to the added voltage. In addition, numerical simulation are performed when the MR damper is used in the ground vehicles as a part of suspension system, while the MR damper is considered in two-stage state and on-off state. The results show that, as a controllable damper, MR damper is very effective for vibration isolation of the vehicle body acceleration and suspension travel, both in on-off state and two-stage state.