Rheological properties analysis and experiment of magnetorheological fluid for automobile

Magnetorheological fluid (MRF) is a new controllable smart material. The viscosity of MRF changes quickly with the variation of applied magnetic field intensity, and the change is reversible, continuous and easy to control, so MRF has wide application in the field of vehicle dampers. The composition, properties and rheological mechanism of MRF are introduced, and three kinds of MRF structural models are analyzed and compared with each other. The MRF rheological properties experiment is done, which shows that MRF has saturable and shear-thinning characteristics and the shear yield stress increases with the increase of magnetic field. But the shear yield stress decreases when the magnetic field is big enough. The bi-viscous model is amended according to experiment. The MRF damper characteristics experiment is done, and the results show that the damper force increases with the increase of impressed current. When the current reaches a certain value, the damper force keeps stable, which shows that MRF has controllability.