Abstract: From the view point of practical research and feasible structure, the establishment of an accurate mechanical model for the magnetorheological damper is one of the key factors for designing control strategy to obtain good control effect. According to various requirements of the vehicle suspension, computation and analysis of the effects of all parameters of magnetorheological damper on the damping characteristic are necessary for the design of modern vehicles. According to the requirements of vehicle damper and the principle of magnetic circuit, a magnetorheological damper of single output bar and damping hole type is designed. Based on the fluid mechanics theory and the rheological characteristics of magnetorheological fluid, a theoretical calculation model for the damping force of magnetorheological damper is deduced. The characteristics of the magnetorheological damper are analyzed and calculated, and the influence of the damper structural parameters on the damping characteristics is studied. The velocity characteristics of the magetorheological damper from the experiment are adopted and the damping force-velocity curves at different current outputs are obtained. The test results are in agreement with the theoretical calculation values. The mechanical model of magnetorheological damper deduced by adopting fluid mechanics theory can provide reliable theoretical direction for the establishment of the damper control model.

Key words: Bingham model, Damping characteristic, Magnetorheological damper