SOME VISCO-PLASTIC CHARACTERISTICS OF BOVINE AND HUMAN CORTICAL BONE
SOME VISCO-PLASTIC CHARACTERISTICS OF BOVINE AND HUMAN CORTICAL BONE
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DOI：
10.1016/0021-9290(88)90200-x
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发表时间：
1988-01-01
影响因子：
2.4
通讯作者：
MICHAELS, C
中科院分区：
文献类型：
--
作者：
FONDRK, M;BAHNIUK, E;MICHAELS, C
对人和牛皮质骨样本进行多周期拉伸蠕变试验。这些试验使总应变能够分解为弹性、线性粘弹性、蠕变和永久塑性分量。结果表明，存在一个应力阈值，以上的时间依赖性的影响占主导地位的材料响应，低于该行为主要是线性粘弹性，时间效应只发挥次要作用。高于阈值的恒定应力产生恒定稳态蠕变速率，蠕变速率的大小是应力大小的指数函数。此外，人们发现，非弹性应变的主要部分总是恢复卸载和蠕变应变的积累增加了材料的后续负载低于阈值的顺应性。这两个因素表明，损伤机制是负责的非线性行为。
Multiple cycle tensile creep tests were performed on human and bovine cortical bone specimens. The tests enabled total strain to be decomposed into elastic, linear viscoelastic, creep and permanent plastic components. The results indicate that a stress threshold exists; above which time dependent effects dominate material response and below which the behavior is primarily linear viscoelastic, with time effects playing only a secondary role. A constant stress above the threshold produces a constant steady state creep rate, with the magnitude of the creep rate being an exponential function of the stress magnitude. Additionally, it was found that a major portion of the inelastic strain is always recovered on unloading and that the accumulation of creep strain increases the materials compliance on subsequent loadings below the threshold. These two factors suggest that a damage mechanism is responsible for the nonlinear behavior.