Development and experimental characterization of a large-capacity magnetorheological damper with annular-radial gap

Magnetorheological (MR) dampers with bypass arrangements and combined annular-radial fluid flow channels have shown superior performance compared to conventional MR dampers with single annular/radial fluid flow gaps. Achieving a higher controllable dynamic force range with low off-state but high on-state damping force is yet a significant challenge for developing MR dampers for high payload ground vehicle suspensions. This paper presents the conceptual design, fabrication, and experimental characterization of a mid-sized large-capacity MR damper equipped with a compact annular-radial MR fluid bypass valve. Extensive experimental tests were conducted to investigate the dynamic characteristics of the proposed MR damper considering wide ranges of excitation frequency, loading amplitude, and electrical current. The equivalent viscous damping and the dynamic range were calculated as functions of loading conditions considered. The proposed damper initially realized the maximum dynamic range and damping force of 2.3 and 5.54 kN, respectively. With MR valve design modifications, the maximum dynamic range and damping force were substantially increased, reaching 5.06 and 6.61 kN, respectively. The effectiveness of the proposed MR damper was subsequently identified by comparing its dynamic range with other conventional MR dampers in previous studies. The results confirmed the superior performance of the proposed MR damper and its potential application for highly adaptive suspension systems for off-road wheeled and tracked vehicles.