Research On Optimization Of Geometric Parameters Of Artificial Knee Joint Based On Contact Mechanics

The wear of UHMWPE tibial joint surface is considered to be the fundamental factor affecting the long-term service life of knee prosthesis.The contact area and contact stress are two key indicators to evaluate the wear of prosthesis.The geometric parameters of knee prosthesis and the position of flexion axis directly affect the size of contact area and contact stress.In order to determine the contribution of prosthesis geometric parameters and femoral flexion axis position to prosthesis performance indicators(contact area and contact stress)and their competitive relationship,and to better design knee prosthesis in line with the actual needs.This paper uses i SIGHT platform to build a parametric finite element model of knee prosthesis by integrating Solid Works and Abaqus software to analyze the geometric parameters of prosthesis Line optimization research.Firstly,a parameterizable knee joint prosthesis is established based on the Depuy knee joint prosthesis,and the finite element analysis of the parametric model is performed on the parametric model with displacement control as the load input.The feasibility of the model is verified by comparing the contact mechanics with the Depuy knee joint prosthesis.Secondly,a finite element model of the geometric design parameters of an automated knee joint prosthesis based on the Isight platform was established.The optimal hypercube Latin sampling method was used to randomly sample the variable space,and 100 sample points with the flexion position as the variable and 354 sample points with 7 geometric parameters as variable samples were obtained.Then use the experimental design module in Isight to integrate Solid Works and Abaqus software,and use the flexion position and geometric parameters as input parameters to establish two experimental designs for finite element simulation.Finally,according to the 354 sample points that have been calculated,approximate models based on contact area and contact stress are respectively fitted to replace the finite element simulation,and applied in the optimization design to obtain a set of knee joint prostheses with the smallest contact area.The better model was discussed and compared.Finally,the influence of the position of the femoral flexion axis and the geometric parameters of the knee joint prosthesis on the contact mechanics of the prosthesis and the degree of contribution are obtained,and the competitive relationship between the contact area and the contact stress in the geometric parameters is discussed.A model with better performance indicators than the initial model was obtained through 354 sample points,and the contact area was reduced by 49.38%.An optimal model is obtained through the optimization algorithm,and its contact area is reduced by 56.66%.Comparing the two optimization models,using the optimization algorithm is more conducive to finding the optimal solution of the objective function than using the traditional sample point calculation.