Recently, cellular materials made by the repetition of unit cells, that is, iron lattices have become appealing to mimic the structure of bone. The aim of the study is to choose the most adequate lattice structures, which have the compressive mechanical properties closer to the ones of bone, in the perspective of their use as temporary implants. Five types of unit cells were selected, such as, cubic (C), truncated octahedron (TO), truncated cubic (TC), rhombicuboctahedron (RCO), and rhombitrucated cuboctahedron (RTCO). The mechanical properties were assessed by numerical simulations with a finite-element analysis. The size effect was studied with the comparison of results among samples with different numbers of unit cells. Simulations covered a wide range of relative densities. Graded dense-in and dense-out configurations were constructed with lattices of types RTCO and TO, being the unit cells, themselves graded. Lattice structures RTCO and TO were found to be stable at every relative density studied, while C, TC and RCO lattices are unstable at low densities. The evaluation of size effects was not conclusive, which could be biased by other factors. The Young's modulus of RTCO and TO lattices enable to reproduce the properties of both trabecular and cortical bone, with an appropriate choice of the relative density. To mimic trabecular bone, only RTCO and TO structures with low relative densities, can be used, while arrangements of C, TC and RCO cells can only replicate the properties of cortical bone. Graded cells may have the same properties as non-graded with lower density.

中文翻译：

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用于模拟骨骼特征的细胞铁晶格结构的压缩特性

最近，由单位细胞重复制成的细胞材料，即铁晶格，在模仿骨骼结构方面变得很有吸引力。该研究的目的是从用作临时植入物的角度来看，选择最合适的晶格结构，使其具有更接近骨的压缩机械性能。选择五种类型的晶胞，例如立方体（C）、截角八面体（TO）、截角立方体（TC）、菱形立方八面体（RCO）和菱形截角立方八面体（RTCO）。通过有限元分析的数值模拟来评估机械性能。通过比较不同晶胞数量的样品之间的结果来研究尺寸效应。模拟涵盖了广泛的相对密度。分级密入和密出配置是用 RTCO 和 TO 类型的晶格构建的，它们是本身分级的晶胞。研究发现晶格结构 RTCO 和 TO 在每个研究的相对密度下都是稳定的，而 C、TC 和 RCO 晶格在低密度下不稳定。规模效应的评估并不具有决定性，可能会受到其他因素的影响。 RTCO 和 TO 晶格的杨氏模量能够通过适当选择相对密度来重现小梁骨和皮质骨的特性。为了模拟小梁骨，只能使用相对密度较低的RTCO和TO结构，而C、TC和RCO细胞的排列只能复制皮质骨的特性。分级电池可具有与密度较低的非分级电池相同的特性。