Tensile properties of sheet-based triply periodic minimal surface lattices fabricated using vat polymerization

Additive manufacturing enables the production of lattice structures with tailored mechanical performance. Among these, triply periodic minimal surface (TPMS) lattices have emerged as promising architectures for lightweight and high-strength applications. However, while their compressive behavior has been extensively studied, their tensile behavior remains largely unexplored. This study examines the bulk tensile properties of sheet-based TPMS lattices fabricated via digital light processing, focusing on Gyroid, IW-P, and Primitive topologies at various relative densities. Novel functionally graded Gyroid specimens were first tested to determine the number of unit cells required to capture the bulk tensile response of TPMS sheet-based lattices. The functional grading design of the tensile specimen ensures that premature failure does not occur at the grip and lattice interface. The results show that the tensile properties reduced with the increase in number of unit cells until it is plateaued at 6 × 6 unit cells along the cross-sectional area of the specimen. The bulk tensile responses of different TPMS topologies at different relative densities show that the tensile stiffness exceeds the compressive stiffness, whereas the yield strength is higher in compression than in tension. Among the examined topologies, IW-P exhibited the highest stiffness and strength at higher relative densities, while Primitive performed better at lower relative densities, with Gyroid showing intermediate behavior across the covered range of relative densities, under both uniaxial tension and compression. The results establish quantitative relationships for tension and compression asymmetry in TPMS lattices and provide guidance for designing TPMS-based lattice architectures optimized for tension-dominated applications.