In order to improve the accuracy of the magnetic circuit model of magnetorheological (MR) brakes, a multi-disk MR brake with a nonlinear equivalent magnetic circuit considering the nonlinear magnetic permeability of materials is proposed and developed. The structure diagram and material selection of the multi-disk type MR brake is presented. The nonlinear magnetic permeability of low carbon steel and MR fluid is introduced into the linear equivalent magnetic circuit. Subsequently, electromagnetic field simulations are conducted to study the magnetic field distribution in different MR fluid gaps. Based on the coupling of magnetic field and temperature field, the relationship between the slip heat generation of MR fluid and the magnetic field strength is explored and the temperature simulation of the brake under steady-state and transient conditions is completed. A prototype of the MR brake has been manufactured and its mechanical properties have been tested. The brake can provide a braking torque of 34.8 N m with a coil current of 1.0 A. The experimental results are largely in line with the simulation. Two temperature sensors are installed, and the temperature in the MR fluid gaps is tested. The experimental results indicate that the magnetic-temperature coupling model has a high accuracy.
Wu et al. (Fri,) studied this question.