Magnetorheological Fluid And Its Application In The Prosthetic Knee Joint

In this paper, the existing prosthetic knee structure is large and cumbersome, the operation is not flexible and the cost is too high. With the existing hydraulic damping prosthetic knee joint mechanism as a template, using magnetorheological (MR) fluid damper to replace the hydraulic dampers to produce semi-active. And the mechanical properties of the micro-nano MR fluid are studied theoretically and experimentally, thus the micro-nano MR damping prosthetic knee joint is further developed. The development of the study, not only can reinforce and improve the theoretical basis of MR damping technology, but also has important significance for the further application of MR damping technology.The main work of this thesis are as follows:(1) The mathematical model of the four-pole prosthetic knee joint was established based on the demand of the controllable damping prosthetic knee joint, using the trajectory matching degree of the artificial limb knee in the body movement as the starting point, the motion parameters of the prosthetic knee joint were optimized by Matlab,and the design model of the prosthetic knee joint was obtained.(2) Based on the controllable damping effect of MR fluid damper, the mechanism of micro-nano MR damping prosthetic knee joint was designed and its rationality was analysised.(3) In view of the existing design flaws of MR damping prosthetic knee joint and the application bottleneck, a new type of micro/nano MR fluid was developed, The mechanical properties (mainly shear stress and normal stress) was studied, the experimental result shows that under the same external conditions, the micro-nano MR fluids have better mechanical properties than the MR fluids.