Dynamic analysis of 3D-printed CF-PETG composites with different infill densities

The primary objective of this study was to explore the influence of infill density on the dynamic characteristics of 3D printed components. Polyethylene terephthalate glycol (CF-PETG), a composite material reinforced with short carbon fibers, was selected for its exceptional mechanical, physical, thermal, and energy absorption properties. This research focuses on an experimental and numerical investigation to characterize the dynamic behavior of CF-PETG fabricated using Fused Filament Fabrication (FFF). In this experimental study, the dynamic response of CF-PETG samples with different infill densities (20%, 50%, 75%, and 100%) was examined under varying impact pressures (1.4 bar, 1.7 bar, 2 bar, and 2.4 bar) utilizing the Split Hopkinson Pressure Bar (SHPB) technique. A high-speed camera, the FASTCAM, was strategically positioned to capture the dynamic deformation processes and damage kinetics during the dynamic compression. The results obtained from this experimental and numerical investigation demonstrated that Honeycomb patterns contribute to reducing macro damages by reinforcing the bonds between layers, thereby limiting cracks and delamination. A fill density of 20%, while exhibiting macro damages and eventual fracture even at modest impact pressures, shows a broader range of Von Mises stresses at a pressure of 1.7 bar due to the honeycomb structure. At 2 bars of impact pressure, samples with a fill density of 50% exhibit macroscopic damages, underscoring the importance of density in impact resistance. However, a fill density of 75% stands out for its superior strength and consistency compared to densities of 100% and 50%, offering increased flexibility while maintaining structural robustness.