Modeling of bionically inspired antifriction and connecting layers in a joint endoprosthesis
This paper presents a stress and strain analysis of the antifriction layer and connecting layer in a joint endoprosthesis which imitate their biological counterparts such as articular cartilage and connective tissue between the joint and the bone. A three-dimensional elasticity problem is solved under the assumption of macroscopic homogeneity, transversal isotropy, and small thickness of these functional layers in comparison with the characteristic size of the zone subjected to surface loading. The general solution for arbitrary boundary conditions is obtained as a series in powers of a small parameter equal to the ratio of layer thickness to contact zone radius. The resulting solution provides more accurate estimates of the stress-strain state parameters than the known Winkler and Pasternak elastic foundation models. The developed micromechanical models are generalized to describe the deformation of gradient subsurface layers of a polymer joint endoprosthesis.