Fracture Mechanics Performance of Through-Thickness Crack of Polymeric 3D Printed Components

This experimental study aims to explore the failure behavior of a pre- and post-cracked polymeric 3D printed components subjected to tensile mode. A set of through-thickness pre-cracked specimens of different cracks patterns and geometry was designed and implemented in the 3D printed parts. The specimens are then subjected to a tensile test mode. Besides, analogous intact samples were produced by 3D printing technology where the through-thickness post-cracks were created using laser cutting process of a geometry with cracks similar to those of the pre-cracked specimens. It has been observed that the pre-cracked samples initially introduced, and 3D printed cracked specimens have more resistance to fracture mechanics failure due to crack-bridging caused by the 3D printing filament profile around the crack profile. On the other hand, the samples with post-cracks made by laser cutting demonstrated a significant drop in the fracture failure resistance due to the interruption of the 3D printed filaments of the intact specimens. In conclusion, this study revealed that pre-cracked 3D printed components did not show the actual failure and fracture mechanics behavior. This is because the cracks could be introduced in the components after the additive manufacturing process during the service life and that would damage the 3D printed filament path of the components and, hence, will cause high-stress concentration that leads to unpredicted and fast failure.