PSI - Issue 41

Mohamed Amine Belyamna et al. / Procedia Structural Integrity 41 (2022) 372–383 Mohamed Amine Belyamna et al. / Structural Integrity Procedia 00 (2022) 000–000

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Table1. Input Parameters used in parametric calculations

Pipe size1

Pipe size2

Pipe size3

Inside diameter(mm) Wall thickness(mm)

88

364 21.3

549 26.4

8.6

Randomized M-PRAISE input values with adjustment of 0,75

Welding residual stress(MPa)

Stress at ID-size1: Mean=168, SD=100

Stress at ID-size2: Mean=64, SD=98

Stress at ID-size3: Mean=262

Flow stress of piping material (MPa) Initial flow distribution (mm)

Normal distribution Mean = 296 and Standard deviation =29

Lognormal distribution Deterministic flaw depth = 0.025

Mean flaw length =3.2 Shape parameter =0.85

Fig. 3. Field observations of leak probabilities compared with the actual results.

4.2. Effect of Pipe Size on the Time Dependence of Probabilities

Once the ANN is trained for a specific pipe, it could be used to estimate the reliability for the future operating lifetime when the needed parameters are obtained. For a given value of IG SCC D  , the Table 1 is used to evaluate the failure probability as function of time. Figure 4 provides a plot of these results. Such results are printed out for each evaluation time.

Fig. 4. Initiation, leak and break probabilities as a function of time for various pipe sizes.