A simulation on growth of multiple small cracks under stress corrosion

In order to keep high reliability of components in a nuclear power plant, it is important to understand the damaging process due to multiple small cracks. The growth shows random behavior because of the microstructural inhomogeneity and the interaction between cracks. The former includes the effects of crack kinking and anisotropic deformation in each crystal of polycrystalline. In this study a Monte Carlo simulation method is developed in order to analyze the random behavior, taking into account the their influences on the stress intensity factor. The damaging process of mill-annealed alloy 600 in the primary water stress corrosion cracking (PWSCC) is numerically simulated by the proposed method. The crack size distribution obtained agrees well with the experimental observation, and the maximum crack size is statistically estimated on the basis of the Gumbel statistics.