The effects of functionally graded structures on contact stress distributions in metal hip joints

This paper uses a finite element analysis (FEA) model to explore the effects of a cellular graded structure on contact stresses occurring on a point loaded spherical geometry similar to that found in a total hip arthroplasty (THA). The results of this study suggest that the application of a cellular structure similar to that naturally occurring in bone significantly reduces maximum shear and Von Mises stresses at the contact site. In addition to reducing stress, the use of a graded cellular structure influences the distribution of stress by moving the peak stress closer to the surface of the geometry in contrast to a solid geometry. Although this paper is preliminary, it suggests a possible method whereby longevity of an implant can be improved through the use of a cellular structure by reducing and redistributing contact stresses.