Orientation driven design and mechanical optimization of gyroid TPMS lattice structures.

Triply Periodic Minimal Surface (TPMS) lattice structures, particularly Gyroid morphologies, are gaining attention for their high specific strength, energy absorption, and geometric adaptability. However, the large body of prior studies has focused on comparing different TPMS topologies or materials, with limited attention to how the build orientation of a single Gyroid structure influences its mechanical behavior. Addressing this gap, this study presents a novel design strategy by systematically varying the build orientation of Gyroid structures fabricated via Fused Filament Fabrication (FFF) using PLA-metal composite. Six models, termed G0 - G5, were created by altering orientation angles relative to the z-axis. Experimental and finite element analyses showed strong agreement and revealed that axially aligned models (G1, G3, G5) achieved significantly higher stiffness, strength, and energy absorption. Homogenization confirmed orientation-dependent anisotropy, and true stress analysis based on CAD-derived cross-sections improved stress accuracy. Increasing wall thickness induced a shift from bending- to stretch- and shear-dominated deformation. Power-law fitting of mechanical properties versus relative density achieved R² > 0.95, validating Gibson-Ashby scaling. These insights support tailored Gyroid designs for crashworthiness, aerospace, automotive and biomedical applications.