The objective of this study is to investigate the energy absorption performance of the graded lattice energy absorbers designed by a stiffness-based size optimization process under static loadings applied during the in-service conditions. The energy absorber geometry is modeled using three different lattice types, namely complex cubic, octet cubic, face- and body-centered cubic. The stiffness-based size optimization subjected to a static bending load is conducted to determine the optimal strut diameters which produced graded lattice structure designs. To investigate the energy absorption behavior of these graded lattice designs, the nonlinear dynamic explicit finite element analysis (FEA) is conducted under quasi-static compression for each design. The lattice designs are fabricated by a material extrusion technique using the polylactic acid material and the quasi-static uniaxial compression tests are conducted on the fabricated designs. The FEA results are found to be in good agreement with the experimental results. When compared with uniform counterparts, the presented graded lattices exhibit the improved energy absorption in response to uniaxial compression although their designs were derived from a stiffness-based size optimization with bending load.

本研究的目的是研究在服役条件下施加的静态载荷下，通过基于刚度的尺寸优化过程设计的分级晶格吸能器的吸能性能。能量吸收器几何形状使用三种不同的晶格类型建模，即复立方、八位组立方、面心立方和体心立方。进行静态弯曲载荷下基于刚度的尺寸优化，以确定产生渐变晶格结构设计的最佳支柱直径。为了研究这些渐变晶格设计的能量吸收行为，在每个设计的准静态压缩下进行非线性动态显式有限元分析 (FEA)。晶格设计是使用聚乳酸材料通过材料挤压技术制造的，并对制造的设计进行准静态单轴压缩试验。发现 FEA 结果与实验结果非常吻合。与均匀对应物相比，所呈现的渐变晶格在单轴压缩时表现出改善的能量吸收，尽管它们的设计源自具有弯曲载荷的基于刚度的尺寸优化。