Abstract With the continuous advancement of space exploration missions, the mechanical environment for planetary detectors is becoming increasingly severe. As a result, fatigue, fracture, large deformation and other forms of failures are more likely to occur at the load-bearing structures. As a critical part of the load-bearing structure of a goat, goat tibia has remarkable toughness because of its unique microstructures. In this investigation, firstly, the cortical bone of goat tibia was observed by SEM, and the characteristic microstructures in different regions were identified. Secondly, the cross section of cortical bone was loaded by long-term inplane stress, then the toughness of cortical bone in different regions are obtained and compared based on the orientation and distribution of cracks after the load. Thirdly, a simplified FEM model mimicking typical microstructure of the cortical bone is proposed using cohesive modeling, and then the toughening mechanism of the typical microstructure is validated with numerical simulation. Finally, the toughening mechanisms of cortical bone were discussed according to the SEM observation as well as the numerical simulation. This study of the toughening mechanism of cortical bone can be helpful for the biomimetic design of high-toughness structures.

中文翻译：

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骨骼的增韧机制——山羊胫骨显微结构的启示

摘要 随着太空探索任务的不断推进，行星探测器的机械环境日益严峻。因此，承载结构更容易发生疲劳、断裂、大变形等形式的失效。作为山羊承重结构的关键部分，山羊胫骨因其独特的微观结构而具有非凡的韧性。本研究首先对山羊胫骨皮质骨进行扫描电镜观察，识别不同区域的特征性微结构。其次，通过长期的面内应力加载皮质骨的横截面，然后根据加载后裂缝的取向和分布，获得并比较不同区域的皮质骨的韧性。第三，使用内聚建模提出了一种模拟皮质骨典型微观结构的简化有限元模型，然后通过数值模拟验证了典型微观结构的增韧机制。最后，根据SEM观察和数值模拟讨论了皮质骨的增韧机制。对皮质骨增韧机制的研究有助于高韧性结构的仿生设计。