A Novel Magneto-Rheological Shock Absorber for Vibration Control

This project focused on the fundamental understanding of behavior and development of novel magneto-rheological fluid MRF shock absorbers for mechanical systems. The aim of the study was on the feasibility of integrating controllable, semi-active, MRF shock absorbers in the suspension systems of the U.S. Armys High Mobility, Multi-purpose Wheeled Vehicle HMMWV. New MRF damper designs were developed, fabricated and tested to meet and exceed the performance criteria set forth by the original equipment manufacture OEM test results. A nonlinear theoretical model was developed which can predict the performance of the MRF dampers. A unique capacity for bypass valving is included in the proposed design. A critical element of vehicle shock absorbers, bypass valving allows the shock absorber to accommodate high-force impulse loading without failure typical to off-highway environments. Moreover, a nonlinear fluid-mechanics based theoretical model was developed by employing Bingham plastic and Herschel-Bulkey non-Newtonian fluid models. Three dimensional electromagnetic finite element analysis was also performed for establishing a base for the MRF damper design. Extensive experiments were conducted to understand the nonlinear behavior of the new MRF dampers.