Publications by authors named "R M Kulin"
California horses incur a bone fragility syndrome manifested by pathologic fractures. This study investigated gross, radiographic, and histologic features of the disorder as well as relationships with silicosis and levels of heavy metals and trace minerals through a postmortem study of 9 affected and 3 unaffected horses. Bones and soft tissues were evaluated grossly and histologically.
View Article and Find Full Text PDFEffects of age and loading rate on equine cortical bone failure.
J Mech Behav Biomed Mater
January 2011
Although clinical bone fractures occur predominantly under impact loading (as occurs during sporting accidents, falls, high-speed impacts or other catastrophic events), experimentally validated studies on the dynamic fracture behavior of bone, at the loading rates associated with such events, remain limited. In this study, a series of tests were performed on femoral specimens obtained post-mortem from equine donors ranging in age from 6 months to 28 years. Fracture toughness and compressive tests were performed under both quasi-static and dynamic loading conditions in order to determine the effects of loading rate and age on the mechanical behavior of the cortical bone.
View Article and Find Full Text PDFArticle Synopsis
- Rising R-curve behavior in bone during quasi-static experiments highlights the role of microstructural mechanisms in resisting fractures, but past studies haven’t explored how these mechanisms hold up under dynamic loading conditions.
- This study utilizes a modified split-Hopkinson pressure bar and high-speed camera to document the first evidence of R-curve behavior in bone during dynamic loading, revealing lower yet still present crack resistance compared to quasi-static tests.
- Investigations using confocal and electron microscopy indicate that the differences in crack resistance stem from variations in toughening mechanisms when bone is subjected to dynamic versus quasi-static fracture conditions.