Experimental Identification of the Automotive Magnetorheological Shock Absorbers

Abstract

The effectiveness of the shock absorbers in terms of comfort and automotive manoeuvrability is closely linked to the free and forced vibrations generated by the road irregularities and the driver’s orders (acceleration, braking etc.). The passengers mass, the sprung mass parties (car body), the free parties mass (wheels and a part of the suspension), the stiffness and the damping coefficient of the various elements of the car are involved in this process. In the road vehicles’ suspensions field, the dampers control through the valves is an extremely difficult target due to the unpredictable flow’s variation and the pressure difference generated inside them. This was the main reason for developing and using magneto rheological fluids as dampers fluids. The authors have designed and built a complex test bench in order to compare the behaviour of a classical dampers and a magneto rheological one. A high speed National Instruments data acquisition system was used to obtain information about the correlation between the damping force, stroke, and speed, control current, temperature etc. The results were compared with the similar ones supplied by some top level manufacturers.