Cyclic mechanical property degradation during fatigue loading of cortical bone
Cyclic mechanical property degradation during fatigue loading of cortical bone
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DOI：
10.1016/0021-9290(94)00156-1
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发表时间：
1996-01-01
影响因子：
2.4
通讯作者：
Carter, DR
中科院分区：
文献类型：
--
作者：
Pattin, CA;Caler, WE;Carter, DR
疲劳损伤累积已在活骨中得到证实，并被假定为对骨建模和重塑反应的刺激。力学性能退化是疲劳损伤累积的表现之一。本研究检测了皮质骨样本在轴向载荷控制疲劳载荷下割线模量和循环能量耗散行为的变化。研究结果表明，割线模量退化和循环能量耗散大大增加在负载水平以上的临界损伤应变阈值为2500和4000亩的拉伸和压缩疲劳，分别。拉伸和压缩疲劳载荷也导致不同形式的模量退化，在这些阈值以上的负载水平。在低于这些阈值时，骨表现为线性粘弹性材料，即使在较高载荷水平下发生先前的性能退化。循环能量耗散是成比例的2.1功率的应用有效应变范围内的所有负载低于2500亩。在2500 μ m以上，拉伸疲劳载荷引起的循环能量耗散与施加的有效应变范围的5.8次方成比例。压缩疲劳载荷耗散的循环能量与施加的有效应变范围的4.9次方成比例，超过4000 μ Ω。在单一载荷水平下断裂的所有疲劳试验的寿命能量耗散与失效循环次数的0.6次幂的相同幂律拟合良好。2500 μ m的拉伸载荷水平和4000 μ m的压缩载荷水平在活体动物中观察到的范围内，因此这些现象可能在启动活骨组织的重塑反应中起作用。
Fatigue damage accumulation has been demonstrated in living bone and postulated as a stimulus to the bone modeling and remodeling response. Mechanical property degradation is one manifestation of fatigue damage accumulation. This study examines changes in secant modulus and cyclic energy dissipation behavior during axial load-controlled fatigue loading of cortical bone specimens. The findings suggest that secant modulus degradation and cyclic energy dissipation are greatly increased at loading levels above critical damage strain thresholds of 2500 and 4000 mu epsilon in tensile and compressive fatigue, respectively. Tensile and compressive fatigue loading also caused different forms of modulus degradation at loading levels above these thresholds. Bone behaves as a linear viscoelastic material below these thresholds, even after prior property degradation at higher loading levels. Cyclic energy dissipation was proportional to the 2.1 power of the applied effective strain range for all loadings below 2500 mu epsilon. Above 2500 mu epsilon, tensile fatigue loading caused cyclic energy dissipation proportional to the 5.8 power of the applied effective strain range. Compressive fatigue loading dissipated cyclic energy proportional to the 4.9 power of applied effective strain range over 4000 mu epsilon. Lifetime energy dissipation over all fatigue tests to fracture at a single loading level was well fitted by the same power law in the number of cycles to failure raised to the 0.6 power. Loading levels of 2500 mu epsilon in tension and 4000 mu epsilon in compression are within the ranges observed in living animals, and thus these phenomena may play a role in initiating the remodeling response in live bone tissue.