有机相对骨组织力学性能影响的有限元分析

Finite element analysis on the effect of organic phase on mechanical properties of bone tissue

骨组织主要由有机相和矿物质相间排列而成,其显微组织结构与纤维增强材料相似。基于矿化程度构建三种胶原微纤维模型,以原胶原分子和有机交联键为出发点,综合探索有机相对微纤维力学性能的作用机制,再与文献数据进行对照验证。数值结果表明:随着矿化程度的加深,微纤维模型的刚度值和塑性趋势均显著上升。原胶原分子的收缩会导致其弹性模量上升,韧性明显下降。交联键数量增多会提高骨组织的力学性能,也增大骨组织的脆性。研究结果有助于揭示骨组织活性成分和微观结构对其力学性能的影响,为骨组织修复材料的开发提供理论依据。

The microstructure of bone tissue is similar to that of fiber-reinforced composites.It mainly consists of the mineral and organic matters arranged alternately.Three kinds of collagen microfibril models were constructed based on the degree of mineralization.The effect of organic phase on mechanical properties of microfibril was investigated on considering of tropocollagen molecules and organic cross-links.The results were further studied by compared with the literature reported.The numerical results show that the stiffness value and trend of plastic deformation of the microfibril models are significantly improved with the increasing of the degree of mineralization.Shrinkage of tropocollagen molecules results in the increase of elastic modulus and the decrease of toughness.The mechanical properties of bone tissue improve and its brittleness increases with the increasing of the number of cross-links.The results are helpful to reveal the effects of the active constituents and microstructures of bone tissue on its mechanical properties,which can provide theoretical foundations to develop bone repair materials.