| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 810963 | Journal of the Mechanical Behavior of Biomedical Materials | 2013 | 11 Pages |
The mechanism of crack initiation from a clinically relevant notch is not well-understood for crosslinked ultra high molecular weight polyethylene (UHMWPE) used in total joint replacement components. Static mode driving forces, rather than the cyclic mode conditions typically associated with fatigue processes, have been shown to drive crack propagation in this material. Thus, in this study, crack initiation in a notched specimen under a static load was investigated. A video microscope was used to monitor the notch surface of the specimen and crack initiation time was measured from the video by identifying the onset of crack initiation at the notch. Crack initiation was considered using a viscoelastic fracture theory. It was found that the mechanism of crack initiation involved both single layer and a distributed multi-layer phenomenon and that multi-layer crack initiation delayed the crack initiation time for all loading conditions examined. The findings of this study support that the viscoelastic fracture theory governs fracture mechanics in crosslinked UHMWPE. The findings also support that crack initiation from a notch in UHMWPE is a more complex phenomenon than treated by traditional fracture theories for polymers.
Graphical AbstractFigure optionsDownload full-size imageDownload high-quality image (133 K)Download as PowerPoint slideHighlights► The viscous fracture model predicts crack initiation and propagation in crosslinked UHMWPE. ► An advanced numerical model was employed to evaluate the crack tip properties. ► Crack initiation from a notch can occur via two different mechanisms in crosslinked UHMWPE. ► The multi-layer crack initiation phenomenon delays crack initiation from a notch.
