Mechanical Characterization of 3D-Printed Carbon-Fiber-Reinforced PETG with Different Filling Densities Using a Split Hopkinson Pressure bar

Additive manufacturing techniques have been proven effective in various applications. Among the various AM techniques, fused filament fabrication (FFF) is a well-known manufacturing process widely used in industry to create complex structures at affordable costs. This work investigates how process factors affect the compressive dynamic strength of carbon fiber-reinforced PETG (CF-PETG) samples made using the FFF technique. For this purpose, a rectilinear pattern was chosen, and the main process parameter evaluated was fill density, which varied from 20%, 50%, 75% to 100%. The Split Hopkinson Pressure Bar (SHPB) was adopted to carry out dynamic compression tests at different strain rates, i.e. at pressures of 1.4, 1.7 and 2 bar. A fast camera has been also set up to track and record damage histories in the specimens as the strain rate evolved. The fracture mechanisms of 3D-printed CF-PETG composites were carefully investigated. Test results showed that higher filling percentages improved dynamic properties. In addition, the fast camera images revealed that the use of a filling density of 100% resulted in improved performance in terms of both the damage attenuation and crash resistance of the 3D-printed specimens.