Virginia Tech - Wake Forest, Center for Injury Biomechanics, USA.
The Ohio State University, Injury Biomechanics Research Center, USA.
J Mech Behav Biomed Mater. 2021 Oct;122:104668. doi: 10.1016/j.jmbbm.2021.104668. Epub 2021 Jun 29.
The objectives of this study were to develop novel methods for quantifying human rib cortical bone material properties in compression and to compare the compressive material property data to existing tensile data for matched subjects. Cylindrical coupons were obtained from the rib cortical bone of 30 subjects (M = 19, F = 11) ranging from 18 to 95 years of age (Avg. = 48.5 ± 24.3). Two coupons were obtained from each subject. One coupon was tested in compression at 0.005 strain/s, while the other coupon was tested in compression at 0.5 strain/s. Load and displacement data were recorded so that the elastic modulus, yield stress, yield strain, ultimate stress, ultimate strain, elastic strain energy density (SED), plastic SED, and total SED could be calculated. All compressive material properties were significantly different between the two loading rates. An ANOVA revealed that sex alone had no significant effect on the compressive material properties. The interaction between sex and age was significant for some material properties, but this may have been a consequence of the lack of older females in the subject pool. None of the compressive material properties were significantly correlated with age, but were more correlated with sample density. This finding differed for the tensile material properties, which showed stronger correlations with age. When comparing between tension and compression, significant differences were observed for all material properties except for the total SED, once the effects of loading rate and age had been accounted for. This was the first study to quantify the material properties of human rib cortical bone in compression. The results of this study demonstrated that rib and thorax finite element models should consider the effects of loading rate, loading mode, and age when incorporating material properties published in the literature.
本研究的目的是开发新的方法来量化人类肋骨皮质骨在压缩下的材料性能，并将压缩材料性能数据与匹配受试者的现有拉伸数据进行比较。从 30 名受试者（男性 19 名，女性 11 名）的肋骨皮质骨中获得圆柱形试样，年龄范围为 18 至 95 岁（平均年龄 48.5±24.3）。每个受试者获得两个试样。一个试样以 0.005 应变/秒的速率进行压缩测试，另一个试样以 0.5 应变/秒的速率进行压缩测试。记录载荷和位移数据，以便计算弹性模量、屈服应力、屈服应变、极限应力、极限应变、弹性应变能密度（SED）、塑性 SED 和总 SED。两种加载速率下的所有压缩材料性能均有显著差异。方差分析表明，仅性别对压缩材料性能没有显著影响。性别和年龄之间的相互作用对某些材料性能有显著影响，但这可能是由于受试者中缺乏老年女性所致。除了与样本密度的相关性较强外，所有压缩材料性能均与年龄无显著相关性。与拉伸材料性能不同，拉伸材料性能与年龄的相关性更强。当比较拉伸和压缩时，在考虑了加载速率和年龄的影响后，除总 SED 外，所有材料性能均存在显著差异。这是首次在压缩条件下量化人类肋骨皮质骨材料性能的研究。本研究的结果表明，肋骨和胸廓有限元模型在纳入文献中公布的材料性能时，应考虑加载速率、加载模式和年龄的影响。
