Mechanical properties of functionally graded rotating lattice structures fabricated with SLM process

Triply periodic minimal surface (TPMS) based sheet lattice structure, especially the Diamond sheet structure, has higher strength than traditional TPMS network lattice structure. However, the mechanical properties of sheet lattice structures with rotating orientation should be further investigated to utilize the unique properties of lattice structure fully. In this paper, the structure with a graded rotation angle from 0 degrees to 45 degrees (DGRS) is designed and manufactured by selective laser melting (SLM). Then, the mechanical properties of DGRS are compared with that of other lattice samples, namely, non-rotating structure (DNS) and the structure with a uniform rotation angle of 45 degrees along the x-axis (DRS). The experimental results demonstrate that DGRS has the highest plateau stress and more stable stress variation at the post-yield stage than other samples. The numerical simulation exhibits dispersive equivalent stress distribution in DGRS, which could alleviate the local stress concentration in the joint area of the lattice structure. Additionally, DGRS shows superior energy absorption capability.