Design and testing of additive manufactured multifold rotationally symmetric lattice structures by laser powder bed fusion

Lattice structures exhibit periodicity along three orthogonal axes, which limits their mechanical isotropy and design flexibility. In this study, the lattice structures with multifold rotational symmetries were proposed and designed based on body-centered cubic (BCC) structures. The specimens of the proposed structures were fabricated through laser powder bed fusion (LPBF) additive manufacturing technology. A finite element model was constructed to analyze the quasi-static compression behavior of multifold rotationally symmetric BCC lattice structures. The lightweight potential of the additive manufactured structures was evaluated through experiments. The effect of the minimum rotation angle on the manufacturability and uniaxial compressive mechanical behavior of the multifold rotationally symmetric BCC lattice structures was investigated through experimental analysis. The results show that the reduction of the minimum rotation angle improves the dimensional accuracy of LPBF-fabricated multifold rotationally symmetric structures and enhances their overall elastic modulus and yield strength. The lattice structure with higher loading capacity can be achieved by reducing the minimum rotation angle. Experimental and finite element simulation results reveal that multifold rotationally symmetric BCC lattice structures exhibit controllable anisotropy in stress distribution and failure modes compared to conventional lattice structures. This study provides a reference for the application of lattice structures in the design of rotationally moving components such as circular toolholders, shafts, pumps, and impellers.