The purpose of this study is to investigate the effect of the stress concentration on the ball at the interface with the femoral neck of the moular hip prosthesis. The stress concentration is one of the dominant factor on the design of the ceramic balls.
A contact stress analysis problem is formulated using the optimization principle and finite element analysis technique with friction on the ball-neck interface modeled as a two dimensional axisymmetric one. A loading modes are axial compression force and frictional force on the contact surface. A numerical procedure is employed to get the solution for varying angles of tapers of the necks. The results showed that maximum stress is reduced from optimization, but the other stress components are increased. The cone angle has significant effects on the stress and cone angle of self-releasing is obtained.