Influence of magnetic property of test plates on magneto-rheological behavior

This paper investigated the behaviors of magnetorheological fluids (MRFs) under shear mode with magnetic iron and non-magnetic titanium upper plates, respectively. Based on the Stribeck curve and friction coefficient normalization methods, the lubrication states at the chain end/plate contacts were more at a boundary lubrication state. The restriction of magnetic plate on the particles ends migrations under high magnetic field enhanced the field induced friction to increase the yield stress. Therefore magnetic plate prevented sliding of particles with plate and resulted in a higher yield stress than the easier sliding of particle chains ends on non-magnetic plate. The magnetic property of the upper test plate should be properly considered during the tests of MRFs to derive accurate description of the properties of MRF to be used in the design of various MR actuators.