摘要
目的研究骨组织中矿物晶体与胶原纤维的相互作用对显微损伤扩展方式的影响。方法在有限元模型的基础之上引入黏性单元,用拉伸-分离理论来模拟离子键、氢键、范德华力等的作用。结合随机场理论以及概率损伤分析方法,研究上述各种相互作用机制对骨组织中显微损伤扩展方式的影响。结果当矿物晶体与胶原纤维通过离子键相结合时,他们之间的界面难以分离,因此骨组织中容易形成线性裂纹。而对于通过范德华力相结合的骨组织,其界面结合不稳定,因此显微损伤容易向着弥散损伤的方式发展。当矿物晶体与胶原纤维之间是通过氢键而相互作用时,发现在显微损伤积累的初始阶段,其发展方式倾向于线性裂纹,而随着显微损伤的逐渐积累,矿物晶体与胶原纤维之间的作用越来约弱,从而整个显微损伤的发展转变为了扩展损伤。结论本研究的结果有助于理解骨组织中不同成分间的相互作用机制对骨后屈服变形中能量耗散过程的影响,从而进一步探索骨质疏松症以及老年性骨折的机理。
Objective To study the effects of mineral-collagen interfacial behavior on the microdamage progression within bone tissue.Methods Based on the finite element model,cohesive elements were introduced and the traction-separation law was used to simulate the role of ionic interactions,hydrogen bonds and van der waals forces.The effects of aforementioned interactions on the microdamage progression within bone were studied by the random field theory and probabilistic failure analysis.Results Strong interfaces（ionic interactions in both opening and sliding modes） between the mineral and collagen phases might encourage the formation of linear cracks in bone,whereas weak interfaces（van der Waals in opening mode and viscous shear in sliding mode） might facilitate the formation of diffuse damages.In addition,there existed a transitional interfacial bonding strength（hydrogen/van der Waals bonds） that governed the transition of microdamage accumulation from linear microcrack to diffuse damage.Conclusions The results from this study will help to understand the effects of mineral-collagen interfacial behavior on microdamage accumulation in bone and further investigate the underlying mechanism of bone fracture due to osteoporosis or ageing.
出处
《医用生物力学》
EI
CAS
CSCD
2011年第5期413-419,共7页
Journal of Medical Biomechanics
基金
国家自然科学基金资助项目(10872007)
关键词
显微损伤
有限元模型
黏性单元
骨组织
裂纹
生物力学
Microdamage
Finite element model
Cohesive elements
Bone tissue
Crack
Biomechanics
