Mechanical Behavior of Functionally Graded ABS Gyroid Lattice Structures Using Fused Deposition Modeling

Abstract

Functionally graded additive manufacturing (FGAM) is a fused deposition modeling (FDM) technique that steadily varies the ratio of the material distribution in a single specimen depending on a specific function. The gyroid design is used in a variety of applications because of its high porosity, surface area, and its good mechanical properties. This work investigated the relationship between the geometric design and the mechanical performance of the acrylonitrile butadiene styrene (ABS) gyroid structure using FDM. Tensile, compression, and flexural tests were performed to determine the mechanical behavior of the functionally graded lattice structures with controlled infill densities per layer. Results showed that the performance of the ABS gyroids is dominated by their geometrical design. The tensile strength of the single-layered structure increased linearly with respect to the increase in infill density from 15% to 35% however, compression and flexural results from 25% to 35% showed an exponential increase of 175.52% and 112.14%, respectively. Increasing the outer layer density from 15% to 35% for the three-layered structures resulted in an increase in tensile strength up to 62%. It was observed that the three-layered structures having the same amount of infill densities provided similar mechanical behavior in all the tests conducted. Fracture failures occurred in the adjoining layers wherein the density of the interconnected structures is a function of its material distribution.