PSI - Issue 57

Stéphan Courtin et al. / Procedia Structural Integrity 57 (2024) 4–13

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Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Crack growth direction

Fig. 10. (a) Evolution of the numerical crack fronts in the thickness of the mock-up, with the thermal loading #2 (b) Numerical and experimental crack growths, on the bottom face of the mock-up, with the thermal loading #2. 7. Conclusions This paper aimed to apply a  J approach on the so-called PACIFIC experiment permitting thermal fatigue crack propagation in LSY conditions. Comparisons between numerical results and experimental fatigue crack growth data allow to have a good confidence in the modelling approach, and experimental observations, like the fact to only propagate fatigue cracks on the bottom face of the mock-up for the thermal loading #2, are well captured. The numerical results are always conservative, but it has been shown that the level of conservatism of the  J approach depends on the assumptions of the numerical protocol (cyclic elastic-plastic stress-strain curve, shape of the crack fronts and crack growth Paris law). The present authors particularly recommend to carefully choose the elastic-plastic curve when performing a  J approach. Optimizing the codified assumptions like the crack growth Paris law and the closure effect correction could be outlook of this work to obtain more representative numerical results. References Cherepanov, G. P.,Thepropagation of cracks in a continuous medium, Journal ofApplied Mathematics and Mechanics, 31(3), 503-512, 1967. code_aster, https://code-aster.org Eshelby, J. D., The continuum theory of lattice defects, Solids State Phys., 3, 79-144, 1956. Hojo, K., Kumagai, S., 2022. Fatigue crack growth prediction of a pipe with a circumferential surface flaw using ΔJ and reference stress method , in Proceedings of the ASME 2022 Pressure Vessels & Piping Conference, USA. Léopold, G., Curtit, F., Courtin, S., 2017. Thermal fatigue crack propagation in large scale yielding (LSY) conditions: PACIFIC experiment on a 316L quasi-structure, in Proceedings of the ASME 2017 Pressure Vessels & Piping Conference, USA. Li, J., Ancelet, O., Double, A., Chapuliot, S., 2019. Evaluation of fatigue crack propagation by  J approach, in Proceedings of the ASME 2019 Pressure Vessels & Piping Conference, USA. Rice, J. R., A Path Independent Integral and the Approximate Analysis of Strain Concentration by Notches and Cracks, Journal of Applied Mechanics, 35, 379-386, 1968. RCC-MRx, Design and Construction Rules for mechanical components of nuclear installations: high-temperature, research and fusion reactors, AFCEN, Edition 2018. RSE-M, In-Service Inspection Rules for Mechanical Components of PWR Nuclear Island, AFCEN, Edition 2014. salome_meca, https://www.salome-platform.org Zcracks, http://www.zset-software.com/products/z-cracks/