ANALYSIS OF MAGNETIC FLUX, DYNAMIC VISCOCITY AND YIELD STRESS DISTRIBUTION IN MR DAMPER

Abstract

Magnetorheological materials are smart materials where its rheological characteristics can be quickly changed by the introduction of a magnetic field. The electromagnet and a piston submerged in an MR fluid make up the MR damper. The MR fluid solidifies as Electromagnet is subjected to current, and its yield stress changes in reaction the magnetic field that is being used. Therefore, the magnetic field generation is a significant MR damper phenomenon. In this work, the magnetic field generated in the damper and dynamic viscosity was analyzed for the change in coil numbers and MR fluid gap utilizing finite element method using COMSOL Multiphysics. A 2D axisymmetric, quasi-static model was created utilizing auxiliary sweep study by changing current from 1.5–4 A and the number of coils 300,400,500 and 600 effects on the magnetic flux density, yield stress, and dynamic viscosity change caused by externally applied current in the fluid flow gap of the MR fluid were assessed and for the fluid flow gap of 1mm,1.5mm,2mm with 400 coil turns. The inference obtained after the analysis of results are as the current is increased the magnetic flux density is also increasing in the MR fluid and as the magnetic flux intensity increases the yield stress and dynamic viscosity also increases with the current. When the number of turns in coil increases the magnetic flux density also increases proportionally and there by yield stress and dynamic viscosity also increases. When the gap between piston and cylinder increases the magnetic flux density is decreased so there by a decrease in yield stress and dynamic viscosity is observed.