Dynamical Modeling and Experimental Study of a Small-Scale Magnetorheological Damper

This paper introduces a multiphysics finite-element dynamic model for a small-scale magnetorheological (MR) damper. The model includes the analysis of the magnetic flux lines, field intensity, non-Newtonian fluid flow, and evaluation of the resistance force under prescribed motion and standard electrical test signals. A new regularized viscosity definition, which improves model solvability, is employed to describe the quasi-Bingham plastic behavior of the MR fluid. Extensive model validation was performed through comparison with the analytic model presented in the previous work and with the data from experimental testing. This model is intended to be used in the optimization of the MR dampers employed in the development of an upper limb orthosis, for tremor attenuation in patients suffering from pathological tremor.