Design of magnetorheological damper with built-in porous flow channels

Magnetorheological damper (MRD), as a semi-active control actuator, has important applications and development prospects in the field of vibration attenuation. However, design of traditional MRD often face problems such as complex structures and low utilization density of fluids. Therefore, this paper proposes a novel MRD with built-in porous flow channels (MRD-PFC). The magnetic circuit distribution and fluid flow path are changed, and the damping characteristics are improved by integrating the magnetic conductive spherical medium into the piston to form porous and tortuous flow channels. Based on the theoretical analysise of porous medium, the weighted value and the Ergun expansion equation, the mathematical model of damping force is established. The flow field characteristics and finite element simulation analysis of the magnetic flux density distribution at the porous medium part are explained. Then, MRD-PFC is processed and the experimental test of three sets of excitation frequencies is carried out by using the fatigue tensile machine. Finally, the simulation results are compared with the experimental test data. It shows that the established mathematical model can well predict the mechanical properties of the damper. Experiments show that the maximum output damping force of the damper is about 983 N (2.5 A current), and the utilization densities of fluid and structure are 69.689 N/ml and 2.734×10-2 N/mm3 respectively. Compared with the traditional MRD, it is increased by 22.64 % and 30.25 % respectively. The research verifies the dual advantages of MRD-PFC in enhancing the magnetic field effect and fluid path control, and provides a new idea for the design of small space, low cost and high performance MRD.