PSI - Issue 13

Temma Sano et al. / Procedia Structural Integrity 13 (2018) 1154–1158 Author name / Structural Integrity Procedia 00 (2018) 000 – 000

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Fig. 5 Plastic zone size (a) without and (b) with hydrogen.

3.3. Fatigue crack propagation and associated plastic zone evolution

Figures 6(a) and (b) show the plastic zone shapes and sizes produced by loading and reconstructed using the displacement data. In terms of the shape and size, the characteristics of the plastic zone were well reconstructed by using our proposed method. Furthermore, Fig. 6(c) shows the equivalent plastic strain gradients obtained from the two procedures. As also seen here, the displacement-based reconstruction of the plastic zone shows reasonable strain distribution compared to that induced by loading.

Fig. 6 Plastic zones (a) induced by loading and (b) reconstructed using displacement data. (c) Comparison between the equivalent strain distributions obtained by loading and reconstruction from the displacement data.

4. Conclusions

We proposed a novel fatigue crack propagation simulation method by finite element method and confirmed it to be reasonable. Cyclic loading was reasonably considered as well. Elastoplastic analysis including the influence of hydrogen was also considered reasonably. Crack propagation analysis including the influence of hydrogen could be performed by coupling the above three analyses. Acknowledgements This work was supported by JSPS KAKENHI Grant Number JP16H06365. References Kanayama, H., Ogino, M., Miresmaeili, R., Nakagawa, T., and Toda, T., 2008. Hydrogen transport in a coupled elastoplastic-diffusion analysis near a blunting crack tip. Journal of Computer Science and Technology 2, 499-510, Sasaki, D., Koyama, M., Higashida, K., Tsuzaki, K., and Noguchi H., 2015. Effects of hydrogen-altered yielding and work hardening on plastic zone evolution: A finite-element analysis. International Journal of Hydrogen Energy, 40, 9825-9837 Moes, N., and Belytschko, T., 2002. Extended finite element method for cohesive crack propagation. Engineering Fracture Mechanics 69, 813-833