Contact Mechanics of Ultra-High-Molecular-Weight Polyethylene for Artificial Knee Joint

Abstract

To investigate the wear mechanism of the ultra-high-molecular-weight polyethylene (UHMWPE) for an artificial knee joint, the pin-on-disk-type wear test and the numerical analysis of contact mechanics of the UHMWPE are performed. In this analysis, to calculate the cyclic deformation of the UHMWPE, the constitutive equation for cyclic plasticity is used. In the initial stage of the deformation, the UHMWPE is deformed only plastically, but beyond this stage, the wear of the UHMWPE progresses rapidly with weight loss. In this initial stage, the shear stress and the equivalent plastic strain are accumulated by cyclic loading at the contact surface of the UHMWPE and it is expected that the microcracks that create wear particles will be generated at the surface. © 1993, The Japan Society of Mechanical Engineers. All rights reserved.