Simulations of Crack Extensions in Arc-Shaped Tension Specimens of Uncharged and Tritium-Charged-and-Decayed Austenitic Stainless Steels Using Cohesive Zone Modeling

Abstract Crack extensions in arc-shaped tension specimens of uncharged and tritium-charged-and-decayed conventionally forged (CF) 21-6-9 austenitic stainless steels are simulated by two-dimensional finite element analyses using the cohesive zone modeling (CZM) approach with the smooth trapezoidal traction-separation law. The J integrals at the deviation loads of the arc-shaped tension specimens are taken as the reference cohesive energies and the maximum opening stresses ahead of the initial crack tips in the arc-shaped tension specimens are taken as the reference cohesive strengths. The cohesive strengths and cohesive energies are then adjusted to match the maximum loads of the experimental load-displacement curves of the arc-shaped tension specimens. The computational results showed that the computational load-displacement, load-crack extension, crack extension-displacement, and J-R curves of the uncharged and tritium-charged-and-decayed CF steel specimens are compared well with the experimental data.