Analysis And Design Of Magnetorheological Fluid Brake

Magnetorheological (MR) fluids is a dramatic change in rheological properties of the material with application of a magnetic field, which are regarded as the intelligent materials that respond to an applied magnetic field with a change in their rheological properties. In the absence of an applied magnetic field, MR fluids exhibit Newtonian-fluid-like behavior. With application of a magnetic field, its structure and properties changing rapidly within a few milliseconds, the apparent viscosity coefficient increased more than several orders of magnitude. These fluids exhibit a Bingham plastic behavior with the yield stress dependent upon strength of applied magnetic field. Thus MR fluids are viscoplastic fluids because they have the properties of both viscosity and plasticity. Based on this characteristic,Magnetorheological fluid brake is designed to have smooth braking, simple structure, easy to control, fast response, low energy consumption and other advantages. It has widespread application prospect in engineering.Magnetorheological fluid brake device achieves braking by shear force of the MR fluids. Magnetorheological fluid brake has the property that its braking torque changes quickly in response to an external magnetic field.In order to establish the design method of the Magnetorheological fluid brake, in this paper, the MR fluids materials and their applications have been analyzed. Based on the properties that the yield stress of MR fluids can be controlled by applied magnetic field, the viscoplastic flow of MR fluids in the Disk type Magnetorheological fluid brake and Cylindrical Magnetorheological fluid brake are investigated. The equations for the braking torque in the Magnetorheological fluid brake have been established. They provide the theoretical foundation for the design of the Magnetorheological fluid brake. The main work and conclusions in this paper are as follows:(1)The composition of MR fluids, MR effect, and the main performance of MR fluids are presented and introduced.(2)Based on the Bingham model, combined with the working principle of Magnetorheological fluid brake, the viscoplastic flow of MR fluids in the Disk type Magnetorheological fluid brake and Cylindrical Magnetorheological fluid brake are analyzed. The equations for the viscoplastic flow of the MR fluids in Magnetorheological fluid brake are established. The equations for the braking torque in the Magnetorheological fluid brake have been derived.(3)The two basic design principles of Magnetorheological fluid brake are analyzed. The magnetic back track and the control circuits of excitation coil of Disk type Magnetorheological fluid brake and Cylindrical Magnetorheological fluid brake are designed.(4)Utilize ANSYS software to carry out the imitation analysis of magnetic back track, and use the results to guide the design of Disk type Magnetorheological fluid brake and Cylindrical Magnetorheological fluid brake.(5)The experiment scheme of Magnetorheological fluid brake is established.。...