Energy Absorber Using a Magnetorheological Bypass Valve Filled With Ferromagnetic Beads

An energy absorber using a magnetorheological (MR) bypass valve filled with ferromagnetic beads was designed, fabricated, and its performance evaluated empirically. Spherical ferromagnetic beads were randomly packed inside a hollow nonmagnetic stainless steel tube comprising the bypass valve body. A key objective was to understand the interaction of magnetic and fluidic mechanisms as the MR fluid flows through a cylinder of randomly packed ferromagnetic beads. Behavior of the energy absorber using different diameters of ferromagnetic beads was measured using a servo-hydraulic testing machine. The relationship between the damping performance of the energy absorber and the ferromagnetic bead diameter was evaluated in terms of maximum controllable damping force, damping control range, and frequency bandwidth