Promptness and dissipative capacity of MR dampers: Experimental investigations

The experimental analyses of response time and dissipative capability of two prototype magnetorheological semi-active dampers are presented herein. These activities have been conducted during an Italian research project on devices manufactured in Germany. A detailed report of the response time analysis based on experimental data is presented and commented. 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 if special care is paid in designing the whole control chain. The dissipative capacity of the devices is further analyzed under the action of different imposed displacement laws, investigating a large range of displacement amplitudes, frequencies, and feeding currents. Interesting comparisons in terms of energy are finally drawn between magnetorheological damper used in a passive (constant current) and in a semi-active mode (variable current commanded by an energy-based control logic).