Theoretical and experimental studies on a magnetorheological brake operating under compression plus shear mode

Abstract

The torque characteristics of magnetorheological brakes, consisting of rotating disks immersed in a MR fluid and enclosed in an electromagnetic casing, are controlled by regulating the yield stress of the MR fluid. An increase in yield stress increases the braking torque, which means that the higher the yield strength of the MR fluid, the better the performance of the MR brake will be. In the present research an application of compressive force on MR fluid has been proposed to increase the torque capacity of MR brakes. The mathematical expressions to estimate the torque values for MR brake, operating under compression plus shear mode accounting Herschel–Bulkley shear thinning model, have been detailed. The required compressive force on MR fluid of the proposed brake has been applied using an electromagnetic actuator. The development of a single-plate MR disk brake and an experimental test rig are described. Experiments have been performed to illustrate braking torque under different control currents (0.0–2.0 A). The torque results have been plotted and compared with theoretical study. Experimental results as well as theoretical calculations indicate that the braking torque of the proposed MR brake is higher than that of the MR brake operating only under shear.

Synthesis and Characterization of Nano-Particles Based Magnetorheological Fluids for Brake

“…Therefore, regulate the voltage using the speed controller to maintain the same speed (rpm) of the MR brake shaft. Braking torque (BT) is calculated using following formula [7] f i…”

“…The basic phenomena are related to reversible structural changes induced by an applied magnetic field. In MR brake [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21], an increase in fluid's shear stress restricts the rotational movement of the disk and increases braking torque on the disk. Under braking conditions, kinetic energy transfers into heat and thermal thinning of MR fluid occurs.…”

“…To find the effect of synthesized MR fluid on braking torque and temperature distribution, a MR brake test rig has been designed and experiments have been performed. The schematic of MR brake [7] is shown in Fig. 1.The working principle and dimensions of the MR brake have been detailed by Sarkar and Hirani [7].…”

“…The schematic of MR brake [7] is shown in Fig. 1.The working principle and dimensions of the MR brake have been detailed by Sarkar and Hirani [7]. Here, r 1 , r 2 , r 3 are 10 mm, 44 mm and 45 mm respectively.…”

Influence Factor on Magnetization Property of Carbonyl Iron-based Magnetorheological Fluids

“…Yildirim and Genc [26] investigated the thermal conductivity of MRFs in three temperature intervals. Routhier and StAmant [27], Sarkar and Hirani [28] successively researched on the squeeze enhancement effect on the shear stress of MRFs. Liu et al [29] experimentally studied on the effect of additional nanometer Fe 3 O 4 on the sedimentation stability, zero field viscosity, and shear yield stress of silicone oil-based MRFs.…”