Seismic Mitigation of Building Frames using Magnetorheological Damper (TECHNICAL NOTE)

The present study focusses on the damping force control of shear mode magnetorheological (MR) damper for seismic mitigations. Therefore, the semi-active MR damper which can control the vibration is analyzed both experimentally and numerically. Carbonyl iron is used as the magnetic particle and Castrol Magnetec oil as carrier fluid throughout the study. MR damper is designed and fabricated, and its damping force was evaluated experimentally at 2.5 A- 10 V. Shear mode MR Damper is tested in universal testing machine using time history loading. The model was numerically analyzed using Newmark’s method for nonlinear system in MATLAB to control the three storey model building frame taken from the literature. The result indicates that 49.42% reduction in displacement at the second storey and 48.14% in the third storey, respectively. Maximum reduction was observed when damper was kept in the ground floor. The maximum force observed for the MR Damper is 0.777 kN.

Keywords:

Magnetorheological Damper , Magnetorheological Fluid , Mewmark’s Nonlinear method , time history analysis