J-INTEGRAL MEASUREMENTS OF ULTRA HIGH MOLECULAR-WEIGHT POLYETHYLENE

Fracture of ultra high molecular weight polyethylene (UHMWPE) contributes to damage modes occurring on the articulating surfaces of total joint replacement components. To minimize damage through the optimization of component design requires an understanding of the fracture behavior of UHMWPE. A fracture mechanics approach was taken in which J integral tests were performed on three-point bend specimens of two thicknesses. JIC was determined to be 99.5 kJ/m2 and was independent of specimen thickness. The fracture surfaces for both specimen thicknesses showed extensive orientation and failure through multiple layers of material, suggesting that UHMWPE experiences plane stress conditions at the crack tip, regardless of thickness.