Protein viscosity, mineral fraction and staggered architecture cooperatively enable the fastest stress wave decay in load-bearing biological materials
Protein viscosity, mineral fraction and staggered architecture cooperatively enable the fastest stress wave decay in load-bearing biological materials
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蛋白质粘度、矿物质成分和交错结构共同实现了承重生物材料中最快的应力波衰减
DOI：
10.1016/j.jmbbm.2016.02.016
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发表时间：
2016
影响因子：
3.9
通讯作者：
Yong Wei Zhang
中科院分区：
文献类型：
--
作者：
Mahan Qwamizadeh;Zuoqi Zhang;Kun Zhou;Yong Wei Zhang
骨、牙本质、贝壳等承重生物材料的关键功能之一是通过有效地阻尼动态冲击来保护其内部脆弱的器官。这些材料是如何实现这一非凡功能的，在很大程度上仍不得而知。采用系统的有限元分析方法，以纳米尺度为模型材料，研究了应力波在皮质骨中的传播和衰减，考察了蛋白质粘度、矿物组分和交错结构对弹性波衰减的影响。研究发现，交错排列、蛋白质黏度和矿物组分协同作用能有效地减弱应力波。对于典型的矿物体积分数和蛋白质粘度，具有特定特征尺寸和布局的最佳交错纳米结构能够产生最快的应力波衰减，并且矿物血小板的最佳长径比和厚度与实验测量结果非常吻合。相反，当矿物体积分数或蛋白质粘度较高时，结构排列对应力波衰减的影响不大，这表明复合材料的阻尼性能从结构敏感状态进入结构不敏感状态。这些发现不仅大大增加了我们对承重生物材料结构-功能关系的理解，而且为设计具有优异抗冲击载荷的仿生材料提供了有用的指导。
One of the key functions of load-bearing biological materials, such as bone, dentin and sea shell, is to protect their inside fragile organs by effectively damping dynamic impact. How those materials achieve this remarkable function remains largely unknown. Using systematic finite element analyses, we study the stress wave propagation and attenuation in cortical bone at the nanoscale as a model material to examine the effects of protein viscosity, mineral fraction and staggered architecture on the elastic wave decay. It is found that the staggered arrangement, protein viscosity and mineral fraction work cooperatively to effectively attenuate the stress wave. For a typical mineral volume fraction and protein viscosity, an optimal staggered nanostructure with specific feature sizes and layouts is able to give rise to the fastest stress wave decay, and the optimal aspect ratio and thickness of mineral platelets are in excellent agreement with experimental measurements. In contrary, as the mineral volume fraction or the protein viscosity goes much higher, the structural arrangement is seen having trivial effect on the stress wave decay, suggesting that the damping properties of the composites go into the structure-insensitive regime from the structure-sensitive regime. These findings not only significantly add to our understanding of the structure-function relationship of load-bearing biological materials, and but also provide useful guidelines for the design of bio-inspired materials with superior resistance to impact loading.