Experimental validation of a novel magnetorheological damper with an internal pressure control

In the present article, we have investigated the behaviour of magnetorheological fluids under a hydrostatic pressure of up to 40 bar.We have designed, manufactured and tested a magnetorheological damper with a novel architecture, which provides the control of the internal pressure. The pressurewas regulated by means of an additional apparatus connected to the damper that acts on the fluid volume. The magnetorheological damper was tested under sinusoidal inputs and with several values for the magnetic field and internal pressure. The results show that the new architecture is able to work without a volume compensator and bear high pressures. On the one hand, the influence of the hydrostatic pressure on the yield stress of the magnetorheological fluids is not strong, probably because the ferromagnetic particles cannot arrange themselves into thicker columns. On the other hand, the benefits of the pressure on the behaviour of the magnetorheological damper are useful in terms of preventing cavitation.