Seismic performance evaluation of a recently developed magnetorheological damper : experimental investigation

Magnetorheological (MR) dampers have the ability to mitigate natural hazards for structures due to their high energy dissipation features with low power demand. This feature has made the MR damper one of the most popular semiactive damping devices. The present work validates the performance of a single-story reinforced concrete (RC) frame using a reduced scale 10 kN capacity multiple coil MR damper that has recently been developed by the authors. To conduct this test, MR fluid is synthesized and the proposed multicoil MR damper was designed and fabricated. Three RC frames were cast and tested using a loading frame with a capacity of 50 kN. This frame was subjected to earthquake excitation with MR damper placed diagonally at 0 A current, 3 A current, and without MR damper for a better comparison. The comparative performance indicated the reductions in displacements, increase of forces, and changes in crack patterns. The proposed semiactive damper can, therefore, be used effectively as a seismic resilient device in reducing the structural responses in the regions of moderate to high seismicity.