Structure and mechanical properties of crab exoskeletons
Structure and mechanical properties of crab exoskeletons
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DOI：
10.1016/j.actbio.2007.12.010
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发表时间：
2008-05-01
影响因子：
9.7
通讯作者：
Meyers, Marc Andre
中科院分区：
文献类型：
--
作者：
Chen, Po-Yu;Lin, Albert Yu-Min;Meyers, Marc Andre
对大羊蟹（Loxorhynchus grandis）外骨骼（角质层）的结构和力学性能进行了研究。螃蟹外骨骼是一种天然复合材料，由高度矿化的几丁质蛋白质纤维组成，排列成扭曲的胶合板或布利甘模式。在与表面垂直的方向上有高密度的孔管小管。这些小管有双重功能：运输离子和营养，并将结构连接在一起。在干湿试样上分别进行纵向和法向拉伸试验。纵向测试的样品显示出凸形状，在破坏之前没有永久性变形的证据，而在正常方向测试的样品显示出凹形状。结果表明，复合材料的力学性能具有各向异性。采用微压痕法通过厚度测量硬度。外表皮（外层）的硬度是内膜（内层）的两倍。用扫描电镜观察测试后的断口形貌；讨论了断裂机理。(c) 2008材料学报Elsevier Ltd.出版。版权所有。
The structure and mechanical properties of the exoskeleton (cuticle) of the sheep crab (Loxorhynchus grandis) were investigated. The crab exoskeleton is a natural composite consisting of highly mineralized chitin-protein fibers arranged in a twisted plywood or Bouligand pattern. There is a high density of pore canal tubules in the direction normal to the surface. These tubules have a dual function: to transport ions and nutrition and to stitch the structure together. Tensile tests in the longitudinal and normal to the surface directions were carried out on wet and dry specimens. Samples tested in the longitudinal direction showed a convex shape and no evidence of permanent deformation prior to failure, whereas samples tested in the normal orientation exhibited a concave shape. The results show that the composite is anisotropic in mechanical properties. Microindentation was performed to measure the hardness through the thickness. It was found that the exocuticle (outer layer) is two times harder than the endocuticle (inner layer). Fracture surfaces after testing were observed using scanning electron microscopy; the fracture mechanism is discussed. (c) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.