Investigation of load direction on the compressive strength of additively manufactured triply periodic minimal surface scaffolds

Triply periodic minimal surfaces (TPMS) enable the construction of lightweight scaffolds, complex geometry heat exchangers, and energy absorbing materials. Additive manufacturing (AM) has the potential to build such TPMS structures due to its inherent manufacturing freedom and layer-by-layer construction; however, the manufacturing orientation in AM is known to have a significant effect on the resulting mechanical properties. The main contribution of this research is the examination of the effect of manufacturing orientation and TPMS type on the mechanical properties of scaffolds manufactured by fused deposition modeling (FDM), a widely used form of AM. The combination of compressive load direction (0° and 90° with respect to the manufacturing orientation) and TPMS type resulted in large changes in compressive strength. The primitive scaffold achieved the best performance in compression tests. It also had the shortest manufacturing time and smallest quantity of support material needed for FDM manufacture. The TPMS scaffold type combined with the loading direction significantly affected the compressive strength and elastic modulus of the scaffolds, showing the importance of considering both these properties in the design of AM scaffold structures.