Damage rate is a predictor of fatigue life and creep strain rate in tensile fatigue of human cortical bone samples
Damage rate is a predictor of fatigue life and creep strain rate in tensile fatigue of human cortical bone samples
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DOI：
10.1115/1.1865188
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发表时间：
2005-04-01
影响因子：
1.7
通讯作者：
Taylor, M
中科院分区：
文献类型：
--
作者：
Cotton, JR;Winwood, K;Taylor, M
本文报告了四个年龄在53-79岁的人股骨皮质骨的29个疲劳试验的结果。在这些试验中，我们考察了应力、失效循环次数、蠕变应变率和模损率之间的相互依赖关系。对于相同的供体，蠕变速率的行为最近被报道为应力和循环的影响(Cotton，J.R.，Zioupos，R，Winwood，K.，和Taylor，M.，2003，“在皮质骨拉伸疲劳期间的蠕变应变分析”，J.Biomech，J.36，第943-949页)。在本文中，我们首先研究了损伤的演化(每循环的模数下降)是如何与应力水平或“归一化应力”水平(应力除以试件的模数)相关联的，结果表明，模数损失率更适合作为归一化应力的函数。然而，我们在这里发现，在失效周期或蠕变速率与损伤率之间的相关性可以比这三个指标中的任何一个与归一化应力之间建立的更好的相关性。这些数据表明，损伤率可以很好地预测人类皮质骨拉伸疲劳的疲劳寿命和蠕变应变率，用于实际问题和计算机模拟。
We present results on the growth of damage in 29 fatigue tests of human femoral cortical bone from four individuals, aged 53-79. In these tests we examine the interdependency of stress, cycles to failure, rate of creep strain, and rate of modulus loss. The behavior of creep rates has been reported recently for the same donors as an effect of stress and cycles (Cotton, J. R., Zioupos, R, Winwood, K., and Taylor, M., 2003, "Analysis of Creep Strain During Tensile Fatigue of Cortical Bone, " J. Biomech. 36, pp. 943-949). In the present paper we first examine how the evolution of damage (drop in modulus per cycle) is associated with the stress level or the "normalized stress" level (stress divided by specimen modulus), and results show the rate of modulus loss fits better as a function of normalized stress. However we find here that even better correlations can be established between either the cycles to failure or creep rates versus rates of damage than any of these three measures versus normalized stress. The data indicate that damage rates can be excellent predictors of fatigue life and creep strain rates in tensile fatigue of human cortical bone for use in practical problems and computer simulations.