In this paper, the elastic–plastic mechanical properties of regular and functionally graded additively manufactured porous structures made by a double pyramid dodecahedron unit cell are investigated. The elastic moduli and also energy absorption are evaluated via finite element analysis. Experimental compression tests are performed which demonstrated the accuracy of numerical simulations. Next, single and multi-objective optimizations are performed in order to propose optimized structural designs. Surrogated models are developed for both elastic and plastic mechanical properties. The results show that elastic moduli and the plastic behavior of the lattice structures are considerably affected by the cell geometry and relative density of layers. Consequently, the optimization leads to a significantly better performance of both regular and functionally graded porous structures. The optimization of regular lattice structures leads to great improvement in both elastic and plastic properties. Specific energy absorption, maximum stress, and the elastic moduli in x- and y-directions are improved by 24%, 79%, 56%, and 9%, respectively, compared to the base model. In addition, in the functionally graded optimized models, specific energy absorption and normalized maximum stress are improved by 64% and 56%, respectively, in comparison with the base models.

中文翻译：

---

用于优化弹塑性行为的结构化功能梯度多孔晶格结构

在本文中，研究了由双棱锥十二面体晶胞制成的规则和功能梯度增材制造多孔结构的弹塑性力学性能。通过有限元分析评估弹性模量和能量吸收。进行了实验压缩测试，证明了数值模拟的准确性。接下来，执行单目标和多目标优化以提出优化的结构设计。为弹性和塑性机械性能开发了替代模型。结果表明，晶格结构的弹性模量和塑性行为受单元几何形状和层的相对密度的影响很大。最后，优化导致规则和功能梯度多孔结构的性能明显更好。规则晶格结构的优化导致弹性和塑性性能的极大改善。与基本模型相比，比能量吸收、最大应力以及 x 和 y 方向的弹性模量分别提高了 24%、79%、56% 和 9%。此外，在功能梯度优化模型中，与基础模型相比，比能量吸收和归一化最大应力分别提高了 64% 和 56%。与基本模型相比，分别为 56% 和 9%。此外，在功能梯度优化模型中，与基础模型相比，比能量吸收和归一化最大应力分别提高了 64% 和 56%。与基本模型相比，分别为 56% 和 9%。此外，在功能梯度优化模型中，与基础模型相比，比能量吸收和归一化最大应力分别提高了 64% 和 56%。