Multidisciplinary design optimization of an automotive magnetorheological brake design

This paper presents the development of a new electromechanical brake system using magnetorheological (MR) fluid. The proposed brake system consists of rotating disks immersed in a MR fluid and enclosed in an electromagnet, where the yield stress of the fluid varies as a function of the magnetic field applied by the electromagnet. The controllable yield stress causes friction on the rotating disk surfaces, thus generating a retarding torque. The braking torque can be precisely controlled by simply changing the current applied to the electromagnet. Key issues involved in the initial design of the automotive MR brake are presented such as the MR fluid selection, magnetic circuit design, torque requirements, weight constraints, dimensions and temperature. A multidisciplinary finite element analysis is performed involving magnetostatics, fluid flow, and heat transfer analysis to study the behaviour of the system, and to serve as basis for a multidisciplinary design optimization procedure. The results of the optimization procedure are presented and the final design obtained is discussed in detail.