Effect of relative density and strut thickness on dimensional accuracy in lattice structures produced by additive manufacturing

Additive manufacturing of lattice structures offers superior lightweight and energy-absorbing properties across aviation, automotive, and biomedical sectors. However, achieving dimensional precision remains a primary obstacle to ensuring design compatibility and product functionality. To address this challenge, this study introduces a novel comparative analysis of BCC, Diamond, and Octet Truss geometries, specifically focusing on the interplay between infill density and strut thickness. By evaluating PLA-fabricated plates with thicknesses of 0.8 mm, 1 mm, and 1.2 mm through microscopic CAD-to-print comparison, the research identifies critical accuracy thresholds. Findings demonstrate that higher infill ratios significantly enhance structural stability; notably, Octet Truss structures exhibited substantially lower dimensional deviations (0.694%–1.923%) compared to BCC structures (1.25%–3.546%). Furthermore, increasing strut thickness to 1.2 mm reduced deviation rates by up to 50% compared to 0.8 mm struts. These results provide a significant resource for optimizing additive manufacturing parameters, offering new insights into achieving high-precision fabrication for complex lattice systems.