The ultra-lightweight structures with high mechanical properties and energy absorption behaviors are focused on the innovation structural design. The design strategy of implementing novel unit cells within architecture materials such as lattice materials enables the attainment of unparalleled combinations of mechanical properties and functionalities while minimizing weight. The most common method to design light-weight lattice materials is optimizing the geometric configurations of the unit cells. However, changing the geometric boundary of lattice structures can also be a good solution to improve the mechanical characteristics and energy absorption behaviors of the lattice materials. In this work, a novel variable cross-section hollow (VCH) lattice was established to improve the energy absorption capacity. By adding metal strips on the edge of the VCH lattices, a new reinforced variable cross-section hollow (RVCH) lattice with metal strips was developed to further enhance the stiffness and energy absorption capacity. The stainless VCH and RVCH lattices were additively manufactured by Selective Laser Melting (SLM) using an EP-M450H metal 3D printer. The quasi-static compressive characteristics and energy absorption behaviors of RVCH lattices were studied experimentally. Finite element modeling was implemented to study the energy absorption mechanism of RVCH lattices. A parametric analysis based on the finite element models was conducted to study the influence of different metal strips on the energy absorption capacity of RVCH lattices. The results show that the RVCH lattices with metal strips attaching to the vertical edges can signally enhance energy absorption of lattice structures with good load uniformity. Furthermore, the natural frequencies analysis indicate that the higher bending stiffness and the tensile stiffness can be achieved for RVCH lattices. This novel lattice is more stable as a load-bearing structure and more efficient as an energy absorber, which can provide guidance in designing innovative lattice structures with excellent mechanical properties and energy absorption capacity.

中文翻译：

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金属条加固的可变截面空心 BCC 晶格的耐撞性和刚度改进


具有高机械性能和能量吸收行为的超轻结构专注于创新的结构设计。在晶格材料等建筑材料中实现新颖的晶胞的设计策略能够实现无与伦比的机械性能和功能组合，同时最大限度地减轻重量。设计轻质晶格材料的最常见方法是优化晶胞的几何配置。然而，改变晶格结构的几何边界也可以成为改善晶格材料的机械特性和能量吸收行为的良好解决方案。在这项工作中，建立了一种新型的可变截面空心 （VCH） 晶格，以提高能量吸收能力。通过在 VCH 晶格的边缘添加金属条，开发了一种带有金属条的新型增强可变截面空心 （RVCH） 晶格，以进一步提高刚度和能量吸收能力。不锈钢 VCH 和 RVCH 晶格是使用 EP-M450H 金属 3D 打印机通过选择性激光熔化 （SLM） 增材制造的。实验研究了 RVCH 晶格的准静态压缩特性和能量吸收行为。采用有限元建模研究 RVCH 晶格的能量吸收机制。基于有限元模型进行参数分析，研究了不同金属条对 RVCH 晶格吸能能力的影响。结果表明，垂直边缘附着金属条的 RVCH 晶格可以显著增强晶格结构的能量吸收，具有良好的载荷均匀性。 此外，固有频率分析表明，RVCH 晶格可以获得更高的弯曲刚度和拉伸刚度。这种新型晶格作为承载结构更稳定，作为能量吸收器效率更高，可以为设计具有优异机械性能和能量吸收能力的创新晶格结构提供指导。