Semi active control system such as Magnetorheological (MR) damper has drawn significant attention in various fields. Magnetorheological dampers consist of MR fluid which is suspensions of magnetically polarizable particles with a few microns in size dispersed in a carrier liquid as silicone oil. In this study various factors which affect the magnetic flux density are being studied analytically using Finite Element Method Magnetics (FEMM) software. Then Fe3O4 Nano Iron particles are sonicated with silicone oil as 40-60 ratios by weight. This MR Fluid is used to the MR Damper which fabricated and mounted diagonally in the Reinforced concrete frame with and without MR damper for cyclic load test to know the behavior of MR Damper for seismic resistance. The energy dissipation capacity 45% increased and displacement reduced by 43 %.

Keywords: MR damper, MR fluid, Magnetic flux density, Optimal design, RC Frame