In recent years, lattice structures have been widely used in aerospace, automobile, biomedicine, and other fields. Lattice structures are porous structures composed of repeating cellular units. Because of their high-porosity spatial structure and low density, lattice structures have high specific strength, high specific stiffness, good energy absorption ability, excellent thermal and acoustic insulation properties, and so on. [1][2][3][4][5][6] The properties of the lattice structures are defined by the cell structure, cell size, base material properties, and relative densities of the cellular unit.Because of the highly complex spatial structure of lattice structures, it is difficult to manufacture the lattice structures with the traditional manufacturing process. Recently, the development of the additive manufacturing (AM) technologies has made the manufacturing of lattice structures easier. Based on ASTM standard, [3] AM is defined as a process of joining materials to make parts from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing and formative manufacturing methodologies. As a member of the AM, selective laser melting (SLM) has been successfully used to fabricate intricate lattice structures for various applications. [7][8][9][10][11][12][13] However, the lattice structure prepared by SLM usually has errors with the original design. Although the manufacturing error can be reduced by optimizing the processing parameters, the manufacturing error cannot be completely eliminated due to the inherent characteristics of SLM. SLM is a forming method based on multilayer accumulation. During manufacturing, the transition between layers is discontinuous, so it will produce step effect. At the same time, the thermal diffusion in the laser processing area will lead to incomplete melting of the powder in the adjacent area, and the incomplete melting metal powder will adhere to the struts' surface, which will affect the manufacturing accuracy and mechanical property of the lattice structure. Further development on the manufacturing technology of lattice structures and improving the machining accuracy and quality are also the focus of future research.At present, the most common lattice structures include microstrut lattice structure (composed of straight struts and nodes), triply periodic minimal surfaces' lattice structure (consists of several smooth surfaces), and the structure derived from them. The microstrut lattice structures include body-centered cubic (BCC), face-centered cubic (FCC), rhombic dodecahedron (RD), et al. and the triply periodic minimal surfaces' lattice structures include Gyroid cellular (GC), Schoen Gyroid (SG), et al. Because of its simple structure and convenient manufacture, BCC lattice structures been widely studied and applied. [7][8][9] SLM technique offers a viable method for manufacturing highperformance BCC lattice structures, which have good property in absorbing energy, and the Gibson-Ashby model could be adapted to predict BCC lattice mechanical properties fo...

Purpose The purpose of this paper is to identify the energy absorption characteristics of arch micro-strut (ARCH) lattice structure (different from traditional straight micro-strut lattice structure) under high-speed impact, and promote the development of special-shaped micro-strut lattice structure. Design/methodology/approach The study serves to study the anti-impact and energy absorption characteristics of ARCH lattice structure under different strain rates and different unit layers of lattice structure. In this paper, quasi-static compression and Hopkinson compression bar experiments are used for comparative analysis. Findings The results show that the ARCH lattice structure has obvious strain rate effect. When the strain rate is low, the number of layers of lattice structure has a great influence on the mechanical properties. With the increase of strain rate, the influence of the number of layers on the mechanical properties gradually weakens. So the ARCH lattice structure with fewer layers (less than five layers) should be selected as the impact energy absorbing materials at lower impact rate, while at higher impact rate, the number of layers can be selected according to the actual requirements of components or devices space size. Originality/value This study shows that Arch lattice structure has excellent energy absorption performance, and provides a theoretical reference for the application of ARCH lattice structure in energy-absorbing materials. ARCH lattice structure is expected to be applied to a variety of energy absorption and anti-impact components or devices, such as aircraft black box fall buffer components, impact resistant layer of bulletproof and landing buffer device.

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