Feasibility Study on the Storage of Magnetorheological Fluid Using Metal Foams

This article presents an original idea: the use of metal foams to store unexcited magnetorheological fluid (MRF) in such a way such that the fluid mixture can be propelled when excited. This work is motivated by the desire to overcome the need for costly dynamic seals for conventional MRF dampers. The results of metal foam characteristics, possible changes in the content of propelled MRF, and the responses of soaked MRF when excited are presented. A plate-on-plate test rig was developed to investigate the performance of the MRF-soaked metal foam set-up. The shearing performance, response time, gap effects and the influence of different metal foams were investigated experimentally. The results show that the MRF can be magnetically propelled into the gap between the plate and the metal foam surface, and shearing resistance is produced on the rotary plate. Shearing performance is sensitive to the volume of the propelled MRF, gap clearance, and the strength of the external magnetic field. The response of the proposed MRF-soaked metal foam set-up is slower than that of the conventional MRF-filled two-plate configuration simply because it takes time to propel the MRF. This primary investigation shows that MRF-soaked metal foams can produce MR effects.