DESIGN AND CHARACTERIZATION OF MR DAMPER

Three kinds of MR damper, such as valve mode type, direct-shear mode type and squeeze mode type are applied in engineering field. In this paper, a valve mode type MR prototype damper was designed and fabricated for experimental study. The circuit design of MR damper consisted with the bobbin, retainer and outer cylinder. The magnetic analysis with finite element method was performed to define these parameters such as the bobbin length, inner cylinder width, MR fluid gap. Damper characterization was performed on universal material test system (MTS) 810. The vibration frequency, displacement and current were considered as input factors, and the damping force was measured as the output factor. Force versus displacement diagrams and force versus velocity diagrams have been plotted with these factor levels. Further, the damper can be used for building and automotive damper with 1 Hz ~ 5 Hz range.