PSI - Issue 68

Vitalii Antonchenko et al. / Procedia Structural Integrity 68 (2025) 1305–1311 Vitalii Antonchenko et al./ Structural Integrity Procedia 00 (2025) 000–000

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Fig. 1 Cylindrical shell with axial inside crack.

Fig. 2 Cylindrical shell with circumferential inside crack.

To calculate the SIF we will use Chapuliot methodology: From the FEM results we obtain the value of the J-integral along the crack tip. We assume that the plane deformation conditions are satisfied along the full crack tip. Therefore, the stress intensity coefficient K I was obtained using the J-integral. The shape factor for each degree of the polynomial is obtained by the following expression: " = #$ ∗ % & " %## $ $ ' & #((*+,) , (1) where the parameter E: ∗ = /0 $ 1 (2) When using quadratic elements, the average value of the shape factor for each element should be calculated. For the deepest point of the defect A, the three nodes of the element are used: point 1, point 2 and point 3 as represented in Fig. 3. The second characteristic point under consideration is point C at the interface between the ferritic vessel and the cladding (Fig. 3). The corresponding shape factor is the mean value deduced for the adjacent quadratic element in