Design and experimental study of the porous foam metal magnetorheological fluid damper based on built-in multi-pole magnetic core

The porous foam metal magnetorheological fluid damper has a broad application prospect in the field of vibration isolation of precision instruments with small damping force because it does not need complex dynamic seal structure. The traditional single-ring magnetic pole porous foam metal magnetorheological fluid damper has a small effective area for the magnetic core that affects the damper output range due to the geometric constraints of the coil and the low magnetic field utilization. Therefore, in order to increase the effective area ratio of the magnetic core, this article introduces the built-in multi-pole magnetic core into the porous metal magnetorheological fluid damper and integrates four axial wound fan-shaped magnetic poles on the magnetic core to improve the output performance of the damper. The magnetic circuit is analyzed based on Ohm’s law of magnetic circuit, and the mathematical model of damping force is established. Based on this, the important geometric parameters of the damper are determined. The finite element method is used to simulate the magnetic field of the damper, and the output performance of the damper is numerically simulated. The dynamic performance test system of the damper is set up to test the designed damper, and the test data and numerical simulation results are verified with each other. The results show that the damping force peak and dynamic regulation range of the damper designed in this article are higher than those of the traditional porous foam metal magnetorheological fluid damper with magnetic core, which effectively improves the mechanical properties of the magnetorheological fluid damper with porous foam metal.