Promptness and Dissipative Capability of Semi-Active Magnetorheological Dampers

The experimental analysis of response time and dissipative capability of two prototype magnetorheological (MR) semi-active (SA) dampers is presented herein. This activity has been conducted during a Italian research project on devices manufactured in Germany. It is shown how the control delays are strongly dependent on the effectiveness of the electric part of the control hardware, generally being less than 10 ms. A detailed report of the response time analysis based on the above experimental data is presented and commented. The dissipative capacity of the devices is then analyzed under the action of imposed sinusoidal displacements or triangular displacements, investigating a large range of displacement amplitudes, frequencies and feeding currents. Interesting comparisons in terms of energy are drawn between the use of MR damper in a passive (constant current) and in a SA mode (variable current commanded by a control logic).