PSI - Issue 68

Masayuki Arai et al. / Procedia Structural Integrity 68 (2025) 3–8 M. Arai et al. / Structural Integrity Procedia 00 (2025) 000–000

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Fig. 5. Relationship between sickle-joint height and fracture energy, showing a comparison between FE and experimental results.

4. Conclusion In this study, we investigated the effectiveness of the sickle joint as an interlocking structure in improving the fracture energy of CT specimens. Finite element analysis shows that for a small sickle-joint height, deformation and fracture proceed with a slip along the sickle-joint interface. As ℎ increases, stress concentration occurs at the smallest cross-section of the sickle joint part, which leads to stretching. The load gradually increases with displacement in the load–displacement curve up to a maximum value, after which the load decreases gradually with displacement. In this case, the elongation to failure increases with the sickle-joint height, owing to the slip deformation at the sickle-joint interface, and the cracks that occur at the sickle joint are related. The fracture energy, defined from the area of the load–displacement curve of the CT specimen produced using a stereolithography 3D printer was examined and revealed to increase with the sickle-joint height, reaching a maximum value at approximately 6.0 mm, then decreases. References Ahn, B. K., Curtine, W. A., Parthasarathy, T. A., Dutton, R. E., 1998. Criteria for crack deflection/penetration criteria for fiber-reinforced ceramic matrix composites. Composites Science and Technology 58, 1775-1784. Arai, M., 2023. On mechanics of interlocking structures by a sickle joint. Transactions of the JSME (in Japanese) 89, 22-00339. Malik, I. A., Barthelat, F., 2016. Toughening of thin ceramic plates using bioinspired surface patterns. International Journal of Solids and Structure 97-98, 389-399. Rubinstein, A. A., 1990. Crack-path effect on material toughness. Journal of Applied Mechanics 57, 97-103. Wickramasinghe, S., Peng, C., Ladani, R., Tran, P., 2022. Analysing fracture properties of bio-inspired printed suture structures. Thin-Walled Structures 176, 109317.