Grid-by-Grid Fractographic Analysis of Additively Manufactured UV-Cured Resins for Pre-programmable Failure

A multi-scale fractographic analysis was performed to a tensile test specimen according to ASTM D638-I additively manufactured by stereolithography with inherent bottom layers. The asymmetric shape of the sample created a rather complex failure analysis case with varying mode I/mode III crack propagation regimes. Performed multi-scaled approach revealed interconnected 3D formation mechanisms of common fractographic features for the first time on additively manufactured UV-cured resins by stereolithography. Both root cause of failure and damage propagation mechanisms were directly correlated with solid building blocks (BB). Printing grids whose shape is pre-defined during manufacturing appeared on the fracture surfaces in the pre-set dimensions. More strikingly, the river pattern formations were found to be the means of communication between different BBs along different material planes. The measured fractal dimension of river patterns was 1.76 which was almost valid in every point on the fracture surface, which provided a pathway for more sophisticated 3D SEM scanning efforts that may pave way to property mapping. A framework fractographic discussion is provided for further research activities on material/printer development along with mechanical testing.