Mechanical properties of an improved 3D-printed rhombic dodecahedron stainless steel lattice structure of variable cross section

A new modified rhombic dodecahedron lattice structure is proposed by redefining the cross section of the struts of the original one with a shape parameter, and the detailed design method of the proposed lattice structure is also provided. For verification, some representative configurations of the proposed lattice structure were 3D-printed via Selective Laser Melting (SLM) with the material 316 L stainless steel. Quasi-static compression test of the fabricated samples was conducted. Finite element model was also established to investigate the mechanical properties of all the as-designed configurations. Finite element results are in good agreement with the experiment results. Compared with the original lattice structure, the proposed one exhibited better mechanical properties and energy absorption. In addition, the effects of the shape parameter on the deformation mode and the mechanical properties of the rhombic dodecahedron (RD) lattice structures were also discussed, while an optimal shape parameter of the proposed RD lattice structure is obtained.