Experimental validation of a microcracking-based toughening mechanism for cortical bone
Experimental validation of a microcracking-based toughening mechanism for cortical bone
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DOI：
10.1016/s0021-9290(02)00319-6
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发表时间：
2003-01-01
影响因子：
2.4
通讯作者：
Bonfield, W
中科院分区：
文献类型：
--
作者：
Vashishth, D;Tanner, KE;Bonfield, W
已经提出，皮质骨通过在裂纹扩展过程中形成微裂纹来获得其韧性。生物机械30（1997）763; J. Biomech. 33（2000）1169）。本研究的目的是通过实验验证先前提出的基于微裂纹的皮质骨增韧机制。对取自红鹿鹿角的皮质骨致密拉伸试样进行了裂纹萌生和扩展试验。对于这些试验，主断裂裂纹或者扩展到预定的裂纹长度，或者在从缺口开始后立即停止。在两组试样中产生的微裂纹计数在相同的表面积的兴趣周围和下面的缺口，裂纹扩展阻力和裂纹扩展速度进行了分析，有更多的微裂纹在感兴趣的表面积中的扩展比在起始试样中，表明微裂纹的形成后，断裂裂纹的开始继续。裂纹扩展阻力随裂纹扩展而增加，裂纹扩展速度与裂纹扩展曲线呈现出与微裂纹形成相关的特征性跳跃式增加和减少模式。裂纹萌生和扩展的扫描电子显微镜照片显示，形成的正面过程区和唤醒，分别。这些结果支持了皮质骨中基于微裂纹的增韧机制。因此，骨韧性是由其在断裂过程中形成微裂纹的能力决定的。(C)2002爱思唯尔科技有限公司。保留所有权利。
It has been proposed that cortical bone derives its toughness by forming microcracks during the process of crack propagation Q. Biomech. 30 (1997) 763; J. Biomech. 33 (2000) 1169). The purpose of this study was to experimentally validate the previously proposed microcrack-based toughening mechanism in cortical bone. Crack initiation and propagation tests were conducted on cortical bone compact tension specimens obtained from the antlers of red deer. For these tests, the main fracture crack was either propagated to a predetermined crack length or was stopped immediately after initiating from the notch. The microcracks produced in both groups of specimens were counted in the same surface area of interest around and below the notch, and crack growth resistance and crack propagation velocity were analyzed.There were more microcracks in the surface area of interest in the propagation than in initiation specimens showing that the formation of microcracks continued after the initiation of a fracture crack. Crack growth resistance increased with crack extension, and crack propagation velocity vs. crack extension curves demonstrated the characteristic jump increase and decrease pattern associated with the formation of microcracks. The scanning electron micrographs of crack initiation and propagation displayed the formation of a frontal process zone and a wake, respectively. These results support the microcrack-based toughening mechanism in cortical bone. Bone toughness is, therefore, determined by its ability to form microcracks during fracture. (C) 2002 Elsevier Science Ltd. All rights reserved.