The Geometrical Effect on the Von Mises Stress on Ball and Socket Artificial Discs

摘要

Wear has been considered as a major issue for ball andsocket artificial discs. This paper studies the effects of ball radiusand radial clearance of the artificial disc on the von Misesstresses. Different material combinations, used in artificial discs,are compared. FEA simulation using Solidworks has beenconducted for different disk geometries. The highest von Misesstress was 714MPa for 10mm radius metal against metal design.The lowest von Mises stress was 14.8MPa for 16mm radius of theUHMWPE/CoCr material combination, which exhibited thelowest von Mises stresses for all the radii of the ball and socketarticulation. Considering radial clearance, the lowest von Misesstress was 14.8MPa for 0.015mm clearance of theUHMWPE/CoCr combination. The highest von Mises stress of100.8MPa with a radial clearance of 0.25mm was recorded forthe same combination. There is a strong relation between the vonMises stress and the geometry of the ball and socket of theartificial disc.