Characterization analysis of a MR damper

摘要

In this paper, it is shown that the MR damper's power dissipation capacity is determined by the time spent in the preand the post-yield damping regimes. This time is determined by its design, by the MR fluid's rheological behavior and by the type of movement applied to the MR damper. To analyze those working regimes, two types of movement with different amplitudes have been applied to the MR damper at different magnetic field intensities and excitation frequencies. The first movement is an imposed harmonic movement, and in the second, power controlled unrestrained movement is obtained. These unrestrained conditions are equivalent to those the MR damper handles in a real application. For all the analyzed conditions, the obtained results have shown that when a harmonic movement is imposed on the damper, the MR fluid is forced to work in the post-yield regime for the majority of the cycle. In contrast, when the unrestrained response is measured, the pre-yield behavior becomes more significant. As a result, for equal maximum displacement, the MR damper dissipates more power when a harmonic movement is imposed compared to the unrestrained movement.