Damage mechanisms and failure modes of cortical bone under components of physiological loading
Damage mechanisms and failure modes of cortical bone under components of physiological loading
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DOI：
10.1016/j.orthres.2005.02.008
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发表时间：
2005-09-01
影响因子：
2.8
通讯作者：
Vashishth, D
中科院分区：
文献类型：
--
作者：
George, WT;Vashishth, D
在体外研究了皮质骨在不同生理载荷（包括拉伸、压缩和扭转）下的疲劳损伤发展。在每次测试期间，连续收集应力和应变数据，以监测和统计确定与骨疲劳和/或蠕变失效相关的初级、次级和三级阶段的发生率。分别通过组织学和断口分析确定了由此产生的微损伤和失效模式。拉伸组表现出模式I开裂和疲劳和蠕变的三个经典阶段，表明低裂纹萌生阈值、稳定的裂纹扩展和微裂纹合并导致的最终失效。相比之下，压缩组显示模式II开裂和两阶段疲劳行为与有限的蠕变表明高裂纹萌生阈值，然后突然断裂。扭转组也显示出两阶段疲劳曲线，但表现出混合模式（模式II和III）微裂纹和主要时间依赖性损伤的广泛损伤。因此，发现骨的疲劳行为与生理载荷的各个机械部件唯一相关，后者确定了与疲劳断裂相关的特定损伤机制。(c)2005骨科研究学会。由爱思唯尔有限公司出版。保留所有权利。
Fatigue damage development in cortical bone was investigated in vitro under different mechanical components of physiological loading including tension, compression, and torsion. During each test, stress and strain data were collected continuously to monitor and statistically determine the occurrence of the primary, secondary, and tertiary stages associated with fatigue and/or creep failure of bone. The resultant microdamage and failure modes were identified by histological and fractographic analysis, respectively. The tensile group demonstrated Mode I cracking and the three classic stages of fatigue and creep suggesting a low crack initiation threshold, steady crack propagation and final failure by coalescence of microcracks. In contrast, the compressive group displayed Mode II cracking and a two-stage fatigue behavior with limited creep suggesting a high crack initiation threshold followed by a sudden fracture. The torsion group also displayed a two-stage fatigue profile but demonstrated extensive damage from mixed mode (Modes II and III) microcracking and predominant time-dependant damage. Thus, fatigue behavior of bone was found to be uniquely related to the individual mechanical components of physiological loading and the latter determined the specific damage mechanisms associated with fatigue fracture. (c) 2005 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.