Small-scale MR damper: design, fabrication and evaluation

The results of an experimental investigation on a developed small-scale MR damper for seismic response reduction in buildings are presented in this article. The damper is intended to have a target capacity of 2 kN. The damper was designed and built using the flow mode principle. The MTS servo-hydraulic UTM was used for testing, and the results were obtained as force–velocity and force displacement plots based on real-time data collected by the MTS suite. From the force–displacement curve, energy dissipated by the MR damper for corresponding frequencies has also been determined. To compare the percentage increase in damping force, the force corresponding to all excitation frequencies is obtained and plotted as force velocity. The maximum force was 252.77 N at 1 Hz, and the minimum force was 175.55 N at 0.1 Hz, with the corresponding velocity of 31.22 mm/s at 1 Hz and 3.56 mm/s at 0.2 Hz. The experiment showed that the MR damper’s velocity varies with displacement control and variable excitation frequency. As the excitation frequency/velocity increases, so does the damping force. Furthermore, the energy dissipated by the MR damper increases significantly as the excitation frequency/velocity increases, ranging from 1.72 to 2.43 J, demonstrating that the developed small-scale MR damper is suitable for use as a vibration-control device in structures.