Fracture of Ultra High Molecular Weight Polyethylene (UHMWPE) components used in total joint replacements is a clinical concern. UHMWPE materials exhibits stable crack growth under static loading, therefore, their fracture resistance is generally characterized using the J-R curve. The multiple specimen method recommended by ASTM for evaluation of the J-R curve for polymers is time and material intensive. In this study, the applicability of a single specimen method based on load normalization to predict J-R curves of UHMWPE materials is evaluated. The normalization method involves determination of a deformation function. In this study, the J-R curves obtained using a power law based deformation function and the LMN curve based deformation function were compared. The results support the use of the power law based deformation function when using the single specimen approach to predict J-R curves for UHMWPE materials.

The purpose of this study was to examine the effect of precracking preparation techniques on the J-integral static fracture resistance of ultrahigh molecular weight polyethylene (UHMWPE). One set of specimens was razor sharpened while the other set was cyclically precracked prior to testing. The results showed that the energy required for stable crack extension through UHMWPE was dependent on the precrack preparation method.