Influence of Strut Shape on the As-Built Quality and Mechanical Performance of Additively Manufactured Simple Cubic Lattices

Abstract

Lattice structures made by additive manufacturing (AM) are being widely studied in the field of biomedical applications. Their strength and dimensional accuracy are critical to their performance. This study explores how different strut shapes affect the as-built quality and mechanical performance of Grade 23 titanium (Ti64) simple cubic lattices made by electron beam melting (EBM). Three strut cross-section geometries, square, octagonal, and round, were evaluated. Micro-computed tomography (CT) was used to assess dimensional deviations. Finite-element stress analysis predicted the mechanical response. Compression tests were conducted in two orientations to validate the models. Square struts showed the highest geometric accuracy and the best compressive strength, followed by the octagonal and round struts. These geometric deviations translated into mechanical trends: the square-strut lattices showed ∼10 – 20 % higher stiffness and yielding load compared with the round-strut equivalents, with the octagonal struts performing intermediately. These results suggest that square struts are better suited for load-bearing implants. The findings provide guidance for designing more reliable and effective lattice-based medical devices.