Design and numerical analysis of perforated plate lattice structures

The plate lattice structure, a novel mechanical metamaterial, surpasses traditional truss lattice structures in stiffness and strength. However, its closed-walled topology poses challenges for manufacturing using powder or liquid-based additive manufacturing methods. This study addresses this issue by focusing on designing manufacturable plate lattice structures with various perforations. Through numerical simulations, we conducted a parametric study to investigate how different perforations influence the stiffness, isotropy, strength, and buckling resistance of the plate lattice structures. The results demonstrate that perforated plate lattice structures maintain higher stiffness compared to the traditional stretching-dominated octet truss lattice. The degree of stiffness deterioration is dependent on the geometry of the perforations. While plate lattice structures exhibit high stiffness at an extremely low relative density of 0.009, their strength is limited by premature elastic buckling. In contrast, at this relative density, the octet truss lattice demonstrates much greater strength. Interestingly, the introduction of perforations improves the plate lattices' buckling resistance as compared to the unperforated design. With an increase in relative density, the plate lattices' yielding mechanism shifts from elastic buckling-dominated to material plasticity-dominated. Moreover, when compared to other lattice structures in literature, it becomes evident that perforated plate lattice structures exhibit superior stiffness and strength, underscoring their considerable potential. The perforated lattices designed in this study contribute to the advancement of infill structures applicable in additive manufacturing and expanding the current state of the art in this field.