Principle, modeling, and testing of an annular-radial-duct magnetorheological damper

Aiming at improving the efficiency of magnetorhelogical (MR) dampers, the principle of an annular-radial-duct MR damper (ARDMRD), in which annular-radial ducts in series in MR fluid flow channel are integrated, is presented and the prototype of the ARDMRD is designed and fabricated. The mathematical model of the ARDMRD considering the nonlinear flow effect of the MR fluid in the flow channel is established. The finite element analysis (FEA) is utilized to validate the principle of the ARDMRD and obtain the magnetic properties of its magnetic circuit. The controllable damping force and equivalent damping of the ARDMRD are tested on the established experimental setup based on MTS 849 shock absorber test system and compared with the theoretical results based on the mathematical model and FEA. The tested controllable damping force of the ARDMRD under excitation velocity of 0.19 m/s is as high as 3149 N and the tested damping force range of the ARDMRD under excitation velocities of 0.025-0.19 m/s is 140-3149 N. The research results show that the designed magnetic circuit structure of the ARDMRD is beneficial to improving the efficiency of the MR damper and the established mathematical model of the ARDMRD can describe and predict its damping force performance accurately.