Abstract: The structure and working principle of a vehicle mono-tube and air-charged magnetorheological fluids(MRF) damper is introduced, and the magnetorheological material in the damper is a new type of intelligent material whose rheological behavior can change with the change of the intensity of loading magnetic field, and the process is reversible. The MRF damper has the features of small volume, great damping force, wide dynamic range, and quick frequency response. The mathematical model of damping force is established by using non-Newtonian fluid model, Bingham plastic model and fluid motion differential equation. The mathematical model indicates the characteristic of damping force. Experiment is done to test the damper characteristics, and the charts of damping-displacement characteristic are obtained with different electric current. The simulation parameters of the damper are obtained through experiment, then the mathematical model of damping force is simulated in Matlab software. The simulation results are compared with testing results. The results show that they agree well, and the damping force mathematical model is proved to be right.

Key words: Damping force, Damping-displacement characteristic, Magnetorheological fluids(MRF) damper