Ductile sliding between mineral crystals followed by rupture of collagen crosslinks: Experimentally supported micromechanical explanation of bone strength
Ductile sliding between mineral crystals followed by rupture of collagen crosslinks: Experimentally supported micromechanical explanation of bone strength
复制标题
DOI：
10.1016/j.jtbi.2009.05.021
复制
发表时间：
2009-09-21
影响因子：
2
通讯作者：
Dormieux, Luc
中科院分区：
文献类型：
--
作者：
Fritsch, Andreas;Hellmich, Christian;Dormieux, Luc
目前正在讨论如何从其内部结构和组成解释骨强度。回顾最近的实验和分子动力学研究，我们在这里提出了一个新的视角骨材料的失败：羟基磷灰石矿物晶体沿着层状水膜的相互韧性滑动，其次是胶原交联断裂。为了将这一愿景转化为数学形式，基于本征应力微非均匀材料的浓度和影响张量的概念，发展了一种用于弹塑性性质升级的多尺度连续介质细观力学理论。该模型反映了骨的层次组织，在代表性的体积元素皮质骨，血管外和细胞外骨材料，矿化纤维和额外的纤维空间，和湿胶原蛋白。为了获得晶体之间界面处的应力状态，额外的纤维状矿物被分解成无限数量的在空间中所有方向上取向的圆柱形材料相。多尺度微观力学模型被证明是能够令人满意地预测不同物种的不同骨骼的强度特性，其矿物/胶原蛋白含量的基础上，他们的晶间，分子间，腔隙，和血管的孔隙度，和羟基磷灰石和（分子）胶原蛋白的弹性和强度特性。(C)2009爱思唯尔有限公司版权所有。
There is an ongoing discussion on how bone strength could be explained from its internal structure and composition. Reviewing recent experimental and molecular dynamics studies, we here propose a new vision on bone material failure: mutual ductile sliding of hydroxy apatite mineral crystals along layered water films is followed by rupture of collagen crosslinks. In order to cast this vision into a mathematical form, a multiscale continuum micromechanics theory for upscaling of elastoplastic properties is developed, based on the concept of concentration and influence tensors for eigenstressed microheterogeneous materials. The model reflects bone's hierarchical organization, in terms of representative volume elements for cortical bone, for extravascular and extracellular bone material, for mineralized fibrils and the extra fibrillar space, and for wet collagen. In order to get access to the stress states at the interfaces between crystals, the extra fibrillar mineral is resolved into an infinite amount of cylindrical material phases oriented in all directions in space. The multiscale micromechanics model is shown to be able to satisfactorily predict the strength characteristics of different bones from different species, on the basis of their mineral/collagen content, their intercrystalline, intermolecular, lacunar, and vascular porosities, and the elastic and strength properties of hydroxy apatite and (molecular) collagen. (C) 2009 Elsevier Ltd. All rights reserved.