Response of a magnetorheological brake under inertial loads

Abstract

The study is objected to investigate the response of a magnetorheological brake (MRB) system under thefree move inertial mass. The disk-type MRB comprises of a rotating disk immersed in magnetorheological fluids (MRFs) and surrounded by an electromagnet coil. The magnetized coil causes a solidification of the MR fluid so that the shear stress between the moving part and static part increases resulting in the decrement speed of the moving parts. The shear stress can be varied by applying different electric current to the coil. The study began with the part design using the3D modeling software, followingbythe magnetostatic analysis. The flux density across the magnetorheological fluid could be predicted through this finite element magnetic simulation. The quantity of magnetic flux was then used to predict the shear stress between static and moving parts. The fabricated MRB was integrated onto a test rig which employs load cell and speed sensor as well as completely instrumented with data acquisition.Since the MRB test rig performed a simple free rotation system, a linear second order differential equation was derived to model the stopping time and braking torque behaviors. The equation of motion was built in a Simulink model, and the simulation results were compared to the real measurement. The achievable braking torque was also presented based on theaverage value from the load cell.