Abstract：a magneto-rheological(MR) grease damper based on multi-stages radial flow mode is put forward in view of low magnetic field utilization resulting from short channels and performances degradation resulting from MR fluid settlements. An analytical model is set by dividing symmetrically damping channel into radial source flow channel and radial confluent flow channel. Flow differential equation in quasi-steady radial flow is obtained from MR grease micro-element force equilibrium at radial coordinate. Both radial flow velocity profile and radial pressure distribution are obtained by solution the flow differential equation using MR grease Bi-viscous constitutive model and no-slip boundary condition. Diagram of radial flow velocity with various radial coordinates are plotted by means of the radial flow velocity profile. The damping force algorithms of MR grease damper also are obtained by integration of radial pressure gradient with respect to radial coordinate. In order to validate rationality of the analytical model, a MR grease damper based on multi-stages radial flow mode is designed and fabricated in accordance with technical requirements of railway vehicle anti-hunting vibration isolation system. The experimental test from J95-I Shock Absorber Test-bed with sine wave excitation are accomplished under the condition of piston peak velocity 0.025m/s, oscillation amplitude 25mm and coil electric current range from 0.2 to 1.0 A in increments of 0.2 A. The experimental results reveal that analytical damping forces vs. disk displacements diagram are in good agreement with experimental those.
2013, Vol. 32 
