Additive manufacturing using Fused Filament Fabrication (FFF) has witnessed significant growth due to its cost-effectiveness, design flexibility, and rapid prototyping capabilities. However, one of the inherent challenges associated with FFF technology is the anisotropy resulting from the layer-by-layer deposition process. This anisotropy can compromise the overall mechanical performance and structural integrity of the printed parts expected to be loaded in more than one orientation.
In an effort to address this limitation, the utilization of Triply Periodic Minimal Surface (TPMS) infill structures has shown promise in enhancing the isotropic behavior of FFF-manufactured components. TPMS structures are naturally occurring and mathematically optimized matrices that efficiently distribute their mass and offer a height strength to weight ratio. This study seeks to evaluate and compare the mechanical properties of three common TPMS structures, namely Gyroid, Schwartz-P, and Schwartz-D, to determine the best candidate for use as infill in applications requiring isotropic behavior.
The thesis analyzes stress and strain data from the three structures at three different density levels. The ultimate tensile strength, elastic modulus, yield strength, and energy absorption are derived and compared. A correlation analysis reveals the structure of infill has a greater influence than the density of infill on mechanical properties and the Gyroid structure is identified as displaying the best strength and ductility across all density levels.