Mineralized collagen fibril network spatial arrangement influences cortical bone fracture behavior

JOURNAL OF BIOMECHANICS

卷:66

Article

Wang, Yaohui¹  Ural, Ani¹ 

[1] Villanova Univ, Dept Mech Engn, 800 Lancaster Ave, Villanova, PA 19085 USA

关键词: Mineralized collagen fibril;    Extra-fibrillar matrix;    Cortical bone;    Cohesive finite element modeling;    Submicroscale;   

DOI  :  10.1016/j.jbiomech.2017.10.038

来源: Elsevier

【 摘 要 】

Bone is a hierarchical material exhibiting different fracture mechanisms at each length scale. At the sub-microscale, the bone is composed of mineralized collagen fibrils (MCF). At this scale, the fracture processes in cortical bone have not been extensively studied in the literature. In this study, the influence of MCF size and orientation on the fracture behavior of bone under both transverse and longitudinal loading was investigated using novel 3D models of MCF networks with explicit representation of extra fibrillar matrix. The simulation results showed that separation between MCFs was the main cause of damage and failure under transverse loading whereas under longitudinal loading, the main damage and failure mechanism was MCF rupture. When the MCF network was loaded in the transverse direction the mechanical properties increased as the orientation of fibrils deviated farther from the main fibril orientation whereas the opposite trend was observed under longitudinal loading. The fracture energy was much larger in longitudinal than transverse loading. MCF diameter variation did not affect the mechanical properties under longitudinal loading but led to higher mechanical properties with increasing MCF diameter under transverse loading. The new modeling framework established in this study generate unique information on the effect of MCF network spatial arrangement on the fracture behavior of bone at the submicroscale which is not currently possible to measure via experiments. This unique information may improve the understanding of how structural alterations at the submicroscale due to disease, age related changes, and treatments affect the fracture processes at larger length scales. (C) 2017 Elsevier Ltd. All rights reserved.

【 授权许可】

Free