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

Fig. 4. Illustration of the pre-cracked meshes used with a finite element model representing one quarter of the mock-up.

4. Sensitivity analyses on the cyclic elastic-plastic stress-strain curve As mentioned above, the choice of the cyclic elastic-plastic stress-strain curve remains an issue to use this ΔJ approach. That is why sensibility analyses have been performed in the present study. Therefore elastic-plastic FEA have been carried out with the following assumptions: • Thermal loading #1 on a pre-cracked mesh whose crack length is approximately equal to 11 mm. • Material parameters considered at 20°C. • Considering the shape of Eq. 3, three options for the cyclic elastic-plastic stress-strain curve (see Fig. 5): o The ‘RCC -MRx- E’ option where the Young’s modulus E of the French RCC-MRx code (2018) is used in Eq. 3, leading to consider a yield strength Sy different from the codified value. o The ‘RCC -MRx- Sy’ option where the yield strength Sy of the French RCC-MRx code (2018) is used, leading to consider a Young’s modulus E different from the codified value. o The ‘shifted RCC - MRx’ option where both codified values of the Young’s modulus E and yield strength Sy are used, but leading to shift the Eq. 3 curve. (a) (b)

Fig. 5. (a) 3 options considered for the cyclic elastic-plasticstress-strain curve(b) Differences between the 3 options for very low total strains .