A discussion of joint function, geometry, and material characteristics is presented. The magnitude of the total joint reaction loads for the hip, knee, and elbow joints under a normal loading configuration is shown. Two model geom etries are proposed, a three layered cylinder and a three layered sphere.

A technique based upon stress functions for the elastic solution, including stresses and displacem ents, for a single layered thick wall cylinder with arbitrary symmetric loading is given. The problem is expanded to the three layered cylindrical case, and a solution is presented in which all stress and displacement conditions at the interfaces are satisfied. Numerical examples are presented using parameters representative of condylar geometry and material properties.

The stress solution for spherical geometry under the influence of axially boundary conditions is presented The solution is obtained by expressing the stress com ponents in terms of a stress function using spherical coordinates. The stresses are then expressible in an infinite series. Next, the displacement solution is obtained using the same stress functions. These solutions are then applied to the three layered spherical model. Boundary and interface conditions are satisfied, and the resulting simultaneous equations are programmed for a digital com puter. Results are shown for a particular condylar configuration.