PSI - Issue 39

Dmitry O. Reznikov / Procedia Structural Integrity 39 (2022) 256–265 ReznikovD.O./ Structural Integrity Procedia 00 (2019) 000–000

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Fig. 5 shows the dependences of the probability of failure of the pipeline component on the number of overload cycles N k for two values of the overload factor k OL =1.85 (curve 1) and k OL =1.9 (curve 2). It should also be noted that the probability of failure strongly depends not only on the mean of the overload factor k OL = E {Σ}/ S max , but also on the coefficient of variation of the value of Σ. Fig. 6 presents a comparison of the dependences of the probability of failure on the overload factor for two cases: N k =100 (curve 1) and N k =500 (curve 2).

Fig. 5. Probability of pipeline fracture vs. number of overload cycles. Curve 1: k OL =1.85, ν Σ = 0.05; Curve 2: k OL =1.9, ν Σ =0.05

Fig. 6 Probability of pipeline fracture vs. overload factor. Curve 1: N k =100, ν Σ = 0. 1; Curve 2: N k =500, ν Σ = 0.1

5. Conclusions The article presents a numerical approach to the assessment of the probability of fracture of a pipeline component that is subjected to constant amplitude pressure cycles and multiple overloads. The intensity of the overloads, the initial size of cracks, and the parameters of the Paris equation are assumed to be random values. The presented approach allows dealing with different types of probabilistic distributions. The type and parameters of the probabilistic distributions can be updated upon obtaining additional information on the level of operational loading, defectiveness, and mechanical properties of the structural material. Acknowledgements This work was financially supported by the Russian Science Foundation (grant no. 20-19-00769).