Three-dimensional lattice structures have the advantages of light-weight and strong design ability, and have good prospects in the application for energy absorption. However, there are seldom design methods of three-dimensional lattice structures for energy absorption, especially a three-dimensional lattice structure design method for energy absorption based on energy absorption diagrams has not yet been proposed. The present study establishes a mechanical theoretical model of self-supporting lattice structures for additive manufacturing. The aluminum alloy self-supporting lattice structures are fabricated by selective laser melting (SLM). An improved characterization method on energy absorption diagram is proposed. Energy absorption diagram of self-supporting lattice structures is established based on finite element analysis (FEA) and uniaxial compression experiments. The results show that the envelope lines of shoulder points of three-dimensional lattice structures with various configurations are different, which varies from the foams. A design method of three-dimensional lattice structures for energy absorption is proposed for the first time on the basis of this energy absorption diagram, which is of great significance for the design of energy-absorbing structures in the fields of aerospace, aviation and transportation.

三维点阵结构具有重量轻、设计能力强等优点，在吸能方面具有良好的应用前景。然而，用于能量吸收的三维晶格结构设计方法很少，尤其是尚未提出基于能量吸收图的三维晶格结构设计方法。本研究建立了用于增材制造的自支撑晶格结构的力学理论模型。铝合金自支撑晶格结构是通过选择性激光熔化（SLM）制造的。提出了一种改进的能量吸收图表征方法。基于有限元分析（FEA）和单轴压缩实验，建立了自支撑点阵结构的能量吸收图。结果表明，不同构型的三维晶格结构肩点的包络线因泡沫而异。在此吸能图的基础上，首次提出了一种三维点阵吸能结构的设计方法，对航天、航空、交通等领域的吸能结构设计具有重要意义。