Crack growth evaluation considering weld residual stress distribution in structural discontinuous joints

Katsuyama, Jinya  ; Masaki, Koichi*; Onizawa, Kunio ; Nishiyama, Yutaka ; Kikuchi, Masanori*

To establish a procedure of structural integrity assessment for structural discontinuous nuclear power components, we evaluate the weld residual stress distribution for a saddle-shaped joint on the basis of thermo-elastic-plastic analyses. Using calculated the residual stress, crack growth analyses considering stress corrosion cracking are performed on the basis of S-version finite element method (S-FEM). It is clarified that there is a position where tensile residual stresses in hoop and axial directions against branch tube are produced near the saddle-shape joint. In addition, we confirmed that S-FEM is applicable to analyze the crack growth behavior under complicated residual stress fields, and the accuracy of S-FEM is also verified through the comparison with crack growth evaluation on the basis of influence function method.