Fracture properties of interlocking structure by sickle joints printed with a stereolithography 3D printer

The crack deflection mechanism is very effective in improving the fracture toughness of brittle materials, such as ceramics. In this study, we attempted to improve the fracture toughness using a sickle-joint structure, which is a classical Japanese joining technique. It is an interlocking structure in which the female and male parts are secured in convex and recessed shapes. Finite element analysis was performed on a sickle-joint-containing Compact Tension (CT) specimen to verify the effectiveness of the high toughness achieved by the interlocking structure. The results show that the fracture energy improves approximately fourfold. A similar effect was confirmed by the tensile test results of a CT specimen 3D-printed by stereolithography.