Scanning electron-microscopic observations show that there are many osteocyte lacunae between the circumferential lamellae, which are nonuniform in distribution. The lacunae are elliptical, and their major axes are along the circumferential direction of the osteon, which can be denoted as circumferential elliptical lacunae (CE). The observations also show that there are many circumferential microcracks in the osteons, and these microcracks are initiated from 2 endpoints of the major CE axis. To investigate the effects of the structural characteristics of osteocyte lacunae on the crack-propagated route and squeeze damage resistance of osteons, 3 different osteon models – CE, radially elliptical lacunae (RE), and circular lacunae (CL) – were created. The microcrack initiation and propagation of the 3 different osteon models were calculated and simulated based on progressive damage analysis. The results show that the crack-propagated route of the CE osteons is along the circumferential direction of the osteon, which is consistent with experimental observations, while those of the RE and CL are in the radial direction of the osteon. CE around the osteon in the bone is the result of long-term natural evolution, which is an important factor for bone to have strong fracture toughness.

中文翻译：

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骨细胞腔隙结构特征对骨细胞抗挤压损伤能力的影响

扫描电镜观察显示，圆周板层间有许多骨细胞腔隙，分布不均匀。腔隙是椭圆形的，它们的主轴沿着骨单元的圆周方向，可以表示为圆周椭圆形腔隙（CE）。观察结果还表明，骨单元中有许多圆周微裂纹，这些微裂纹是从 CE 主轴的 2 个端点开始的。为了研究骨细胞腔隙的结构特征对骨细胞裂纹传播路径和抗挤压损伤的影响，创建了 3 种不同的骨细胞模型——CE、径向椭圆形腔隙 (RE) 和圆形腔隙 (CL)。基于渐进损伤分析计算和模拟了 3 种不同骨单元模型的微裂纹萌生和扩展。结果表明，CE 骨子的裂纹扩展路径沿骨子的圆周方向，与实验观察一致，而 RE 和 CL 的裂纹扩展路径沿骨子的径向。骨骼中骨细胞周围的CE是长期自然演化的结果，是骨骼具有强断裂韧性的重要因素。