MECHANICAL AND MORPHOLOGICAL EFFECTS OF STRAIN RATE ON FATIGUE OF COMPACT-BONE
MECHANICAL AND MORPHOLOGICAL EFFECTS OF STRAIN RATE ON FATIGUE OF COMPACT-BONE
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DOI：
10.1016/8756-3282(89)90055-0
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发表时间：
1989-01-01
期刊：
影响因子：
4.1
通讯作者：
BURR, DB
中科院分区：
文献类型：
--
作者：
SCHAFFLER, MB;RADIN, EL;BURR, DB
致密骨标本在单轴拉力下循环加载一百万次；加载在两种生理应变速率（0.01 s-1或0.03 s-1）和生理应变范围（0-1200微应变）中的任何一种下进行。然后对加载和非加载对照标本的微损伤进行组织形态学评估。在两种应变率下都观察到疲劳，并且在高实验应变率下加载的试样比在低应变率下加载的试样明显更大。在形态学上，这种疲劳与骨中微裂纹数量的增加相对应。这些数据表明，疲劳和由此产生的微损伤是在生理应变范围内循环加载的现实预期。应变发展的速度影响致密骨的疲劳行为，表明高生理应变速率的循环加载，剧烈活动的特征，比低生理应变速率的加载对致密骨的损害更大。
Compact bone specimens were cyclically loaded in uniaxial tension for one million cycles; loading was performed at either of two physiological strain rates (0.01 s-1 or 0.03 s-1) and a physiological strain range (0-1200 microstrain). Microdamage in loaded and nonloaded control specimens was then assessed histomorphometrically. Fatigue, evidence by stiffness loss, was observed at both strain rates and was significantly greater in specimens loaded at the high experimental strain rate than in specimens loaded at the low strain rate. Morphologically, this fatigue corresponded to increased numbers of microcracks in the bone. These data show that fatigue and resultant microdamage are realistic expectations of cyclic loading within the physiological strain range. The rate at which strains are developed influences the fatigue behavior of compact bone, suggesting that cyclic loading at high physiological strain rates, characteristics of vigorous activities, is more damaging to compact bone than loading at lower physiological strain rates.