Cellular solids have superior energy absorption capabilities as compared to monolithic materials. Within this category of materials, lattice materials are of particular interest since their periodicity offers repeatable – and thus predictable – behavior. In combination with the advancements in additive manufacturing technologies, these lattice materials can be highly customized for a desired response. In this paper, the crashworthiness of unique multi-layer, multi-topology (MLMT) lattices is investigated. First, the nylon-carbon fiber composite material properties within a developed numerical model were tuned based on strut orientation. Then, the response of single-layer and three-layer cubic and octet lattices was investigated, where all lattices were designed with a relative density of 30%. Following the characterization of single-topology lattices, the response of MLMT lattices were investigated. Stress-strain, efficiency-strain, and multiple crashworthiness parameter data was collected for all lattices to facilitate in the comparison of those lattices. It was found that, experimentally, the unique MLMT lattices did not absorb more energy than their constituent layers combined, though modifications to the interface between layers could increase the energy absorption capability; the prediction of energy absorption of the MLMT lattices based on constituent layers was similar to actual numerical results. As all lattices were designed at the same relative density, the mass-specific energy absorption of the cubic-octet-cubic MLMT lattice (1.56 x103 J/kg) outperforms the single-topology octet lattice by 19% to 36% (1.15–1.31 x103 J/kg). While the octet-cubic-octet MLMT lattice (0.71 x103 J/kg) is outperformed by the single-topology cubic lattices (1.69–3.76 x103 J/kg), they see an increase of 59% to 77% in plateau stress (5.1–9.2 MPa) as compared to the MLMT lattice (2.1 MPa).

中文翻译：

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3D打印多层多拓扑碳纤维尼龙晶格材料的耐撞性研究

与整体材料相比，多孔固体具有卓越的能量吸收能力。在此类材料中，晶格材料特别令人感兴趣，因为它们的周期性提供了可重复的（因此可预测的）行为。结合增材制造技术的进步，这些晶格材料可以根据所需的响应进行高度定制。在本文中，研究了独特的多层、多拓扑（MLMT）晶格的耐撞性。首先，根据支柱方向调整开发的数值模型中的尼龙-碳纤维复合材料特性。然后，研究了单层和三层立方和八位体晶格的响应，其中所有晶格​​均设计为相对密度为30%。在表征单拓扑晶格之后，研究了 MLMT 晶格的响应。收集所有晶格的应力-应变、效率-应变和多个耐撞性参数数据，以便于对这些晶格进行比较。实验发现，尽管对层间界面的修改可以增加能量吸收能力，但独特的 MLMT 晶格吸收的能量并不多于其组成层的总和。基于组成层的MLMT晶格的能量吸收预测与实际数值结果相似。由于所有晶格均以相同的相对密度设计，因此立方-八位组-立方 MLMT 晶格 (1.56 x103J/kg）的性能优于单拓扑八位组晶格 19% 至 36% (1.15–1.31 x103焦耳/千克）。而八位组-立方-八位组 MLMT 晶格 (0.71 x103J/kg）优于单拓扑立方晶格（1.69–3.76 x103J/kg），他们发现与 MLMT 晶格（2.1 MPa）相比，平台应力（5.1-9.2 MPa）增加了 59% 至 77%。