Agglomeration of Magnetorheological Fluid Mass to an Immersed Vibrating Electromagnet

摘要

Dynamic vibration absorbers (DVAs) have been designed with variable spring and damping elements to enable real-time or non-real-time adaptation to vibration conditions. Mass, the third element of a DVA, is more difficult to adjust. The subject paper describes an experimental study of a small electromagnet immersed in magnetorheological (MR) fluid and vibrated at a single frequency by an electrodynamic shaker as force and acceleration data are acquired. When the magnet is energized, MR fluid clings to it, potentially allowing for design of a DVA with variable mass and even damping, as the shape of the electromagnet-MR fluid mass changes. It is found that the effective mass of the system depends on the vibration conditions, with less mass adhering at higher frequencies and displacements, but significant increases in mass are possible at lower frequencies and displacements. The paper outlines the experimental apparatus used, presents data acquired, and proposes a dependency of the effective mass on frequency and displacement.