A Novel Hexagonal-Zigzag Cellular Infill Structure for Additive Manufacturing

Abstract The rigidity of the Additively Manufactured objects can be tailored by manipulating the infill lattice type and density. In this research, an island type novel infill structure termed as Hexagonal-Zigzag pattern is introduced, and its mechanical performance is investigated. In this pattern, the zigzag raster reflects the repeating hexagonal shaped cell constituting the parallel-oriented islands and 90° rotation of the pattern in each layer distributes the island span along both transverse and longitudinal directions of the printing contour. A mathematical model is established to illustrate the effect of the infill parameters on hexagon unit cell size and relative infill density. The compression test is executed on some rectangular test samples to characterize the nature of this pattern and exploring its performance over other existing infill patterns: Honeycomb, Zigzag, and Triangle. The test result reveals that the compressive strength, elastic modulus of the proposed infill pattern is comparable with the Honeycomb infill pattern. Furthermore, the highest plateau stress and absorbed energy density demonstrate the performance of the proposed infill pattern. In addition, the experiment is extended to investigate the mechanical behavior of the proposed infill pattern with various hexagon unit cell sizes. The experimental results reveal the related pros and cons, such as increasing compressive strength and energy density with the enlargement of unit cell size exhibits its efficiency, whereas the decreasing elastic modulus and early densification represent the weakness.