Dynamic Performance of Different Metal Foam Magnetorheological Fluid Materials

This paper investigates the dynamic response of different metal foam magnetorheological (MR) fluid materials experimentally. Metal foam MR fluid materials can be used to manufacture the low-cost controllable damping devices without the need of a seal and provide a long service life. The MR fluid is stored in metal foam mainly by the capillary force. In the action of magnetic field, the MR fluid will be extracted out from metal foam and fill up the shear gap, and then, produce the MR effect. Three types of metal foams with different relative permeability, such as Fe, Ni, and Cu, are applied to store the MR fluid. A set of testing systems, including the plate-on-plate shear test rig, electromotor, and force sensor, is built to investigate the dynamic performance of these materials. In order to describe the dynamic response accurately, three parameters of response time are introduced and defined. The magnetic field, both in the shear gap and the pore of metal foam, is simulated by finite element method software. The experimental results show that the response time of metal foam MR fluid materials will change with different currents, which provides the theoretical and experimental basis for the further development of metal foam MR fluid dampers or actuators.