Investigation on the detailed resistance force of MRF damper

Magneto-Rheological Fluid (MRF) damper has been studied for application to civil and structural engineering. Authors have designed the passive type damper of capacity 60kN which consists of a conventional MRF and permanent magnet. Design methods of damping force generated by fluid flow resistance are estimated by using Newtonian fluid and Bingham fluid mechanics. In particular, design formula about Bingham fluid model is extracted by reference of Buckingham-Reiner equation. Dynamic properties are examined by applying sinusoidal input displacement and by changing orifice diameter. Velocity-force relations and dissipation energy-frequency relations are measured. Damping forces obtained from analytical view and experimental results are compared. And authors have confirmed that both are in good agreement between the analytical view and experimental results.