Scaling effects on the damage and energy-absorption behaviours of 3D printed continuous carbon fibre-reinforced PLA panels

The scaling effect on perforation resistance of 3D-printed continuous carbon fibre-reinforced polylactic acid (CCF/PLA) composites was studied subjected to quasi-static and impact at low-velocity loading conditions. To investigate the failure modes of the panels subjected to scaling effect. three different sample sizes (n = 1/3, 2/3, 1) have manufactured, based on the 3D printing using CCF/PLA. The load-displacement curves following tests at quasi-static and impact rates of strain are compared and normalized. The normalized study of the load-displacement curve shows that increasing the scale results in a decrease in the peak load. The normalized study of the load-displacement curves indicates that the peak load reduces as the structural scale increases. The experimental results indicate that the normalized total energy absorbed during perforation decreases with increasing panel size, as the larger panels exhibit greater levels of fibre fracture, resulting in greater damage accumulation. Additional emphasis was placed on evaluating both the extent of damage and the corresponding energy dissipation characteristics of the scaled specimens. Energy-absorption during the quasi-static perforation process was slightly higher (2 %) than under impact conditions. For the same scale size, the normalized crack length following low-velocity loading was approximately double that under quasi-static loading. The results highlight size effects in the perforation resistance of 3D printed CCF/PLA composites. Finally, it is concluded that care has to be adopted when interpreting the results of scaled 3D printed composite components.