A WEAR MODEL FOR UHMWPE WITH APPLICATION TO THE KNEE PROSTHESES

Andrei TUDOR

tudor@meca.omtr.pub.ro

Alina CHESNOIU

Georgiana BOSOI

"Politehnica" University of Bucharest, Romania

Abstract. Tribological phenomena in the knee prostheses contact define the durability of knee prostheses. The dimensionless Von Misses parameter is used to limit the elastic deformation for a hertzian contact of the femoral metallic component with the tibia and the patellar polyethylene components. Dimensionless contact pressure is obtained by superposing the elastic normal and friction stresses. The mechanical wear model is defined by the fatigue strength of polyethylene material at the walking parameters. The effects of body weight, angles of bending and rotation of femural component relatively to the tibia are analyzed.

Keywords: fatigue wear, wear maps, durability, knee prostheses