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Abstract
The interface friction exists in natural and artificial joints as well as many engineering systems in which different bodies articulate. It often plays an important role in mechanics of the system. In cementless arthroplasty, the friction between the prosthesis (including stems and screws) and the host bone is exploited to increase the fixation of the artificial joint. The experimental studies have shown that the interface between the cancellous bone and various porous coated metals exhibits a nonlinear friction that remains nearly the same in different directions; a nonlinear isotropic friction. More recent bi-directional friction tests between cancellous bone or polyurethane cubes and a metallic plate with porous surface have demonstrated that the interface load-displacement curve is highly nonlinear with significant coupling between two perpendicular directions. Model studies incorporating measured nonlinear interface friction response have demonstrated the importance of proper simulation of nonlinear friction as compared with the Coulomb friction for the prediction of accurate results and the coupling between orthogonal directions. In this study, we aim to extend the earlier model studies to incorporate nonlinear direction-dependent anisotropic friction between two surfaces at contact. (Abstract shortened by UMI.)
