On the Size and Notch Effect in AM Photo-Polymerized Components

The mechanical and fracture properties of components obtained by digital light processing technology are strongly influenced by process parameters like exposure time, specimen orientation, curing treatment, and so on. On the other hand, the 3D printed component with DLP technology shows a brittle behavior. In this work, we investigated the size and the notch effect on printed components obtained using Anycubic Photon printer. Two different resins were used to 3D print the doge-bone, Single Edge Notch Bend and Semi-Circular Bend specimens. The tensile test results and fracture toughness were used to determine the critical distance. Then, semi-circular bend specimens having different sizes and notches were used to investigate the size and notch effects. A strong size effect of the two considered resins was experimentally demonstrated, which agrees well with the asymptotic matching that describes a smooth transition between the strength of materials criterion with no size effect and linear elastic fracture mechanics. Our results highlight that the theory of critical distance is capable of accurately modeling the detrimental effect of notches, respectively predicting the fracture load.