Design and Performance Evaluation of a Rotary Magnetorheological Damper for Unmanned Vehicle Suspension Systems

Abstract

We designed and validated a rotary magnetorheological (MR) damper with a specified damping torque capacity, an unsaturated magnetic flux density (MFD), and a high magnetic field intensity (MFI) for unmanned vehicle suspension systems. In this study, for the rotary type MR damper to have these satisfactory performances, the roles of the sealing location and the cover case curvature of the MR damper were investigated by using the detailed 3D finite element model to reflect asymmetrical shapes and sealing components. The current study also optimized the damper cover case curvature based on the MFD, the MFI, and the weight of the MR damper components. The damping torques, which were computed using the characteristic equation of the MR fluid and the MFI of the MR damper, were 239.2, 436.95, and 576.78 N·m at currents of 0.5, 1, and 1.5 A, respectively, at a disk rotating speed of 10 RPM. These predicted damping torques satisfied the specified damping torque of 475 N·m at 1.5 A and showed errors of less than 5% when compared to experimental measurements from the MR damper manufactured by the proposed design. The current study could play an important role in improving the performance of rotary type MR dampers.

Development of a new torsional vibration damper incorporating conventional centrifugal pendulum absorber and magnetorheological damper

“…The magnetic field is generated in the FE model based on 400 coil turns with wire size 24 gauge (0.5105 mm diameter) and an electric current of 1.6 A. As it can be seen from Figure 5, the magnetostatic FE analysis shows maximum magnetic flux density value of 1.525 T near the electromagnetic coil which is an optimal desired value since it is lower than the saturation limit (;1.6 T) of the chosen structural steel (SS-400) for the housing of the MR damper (Lee et al, 2013).…”

Experimental validation of a novel magnetorheological damper with an internal pressure control

“… ϕ is the iron particle volume percentage in the MRF. The yield shear stress τy(Hmrf) is given by the experimentally derived equation from Lee et al (2013) and Yoo and Wereley (2002), and it depends on the magnetic field intensity and the particle volume fraction ϕ…”

Design of a novel magnetorheological damper with internal pressure control

“…Firstly, the knowledge of the yield shear stress of the fluid as function of the magnetic field is necessary. The yield stress τ B H mrf of MRF 140-CG [15] is given by the experimentally-derived equation from [16,17] and depends on the magnetic field intensity and the particle volume fraction φ: where, B is in Tesla, H mrf is in A/m, and μ 0 = 1.25x10 -6 H/m is the permeability of free space. Fig.…”