Failure of polyamide 12 notched samples manufactured by selective laser sintering

Fracture resistance of polyamide 12 was measured with tensile tests on notched specimens with different notch tip radii. The specimens were processed by additive manufacturing techniques, and the tests were carried out in two different orientations to evaluate the potential anisotropy of the material. Finite element analysis was performed to know the stress state of the whole specimen. Then, the failure of the specimens was described using the theory of critical distances. The influence of possible manufacturing defects in the material was incorporated using a probabilistic approach, associated with a Weibull distribution. A fractographic analysis of the post-mortem specimens allowed to identify those mechanisms responsible for the material failure in each orientation