Comparison of KI calculation methods

• The accuracy of different numerical methods of SIF calculation is compared.
• XFEM method shows advantages in modeling crack.
• XFEM shows oscillations due to extraction domains for J and interaction integrals.
• The best results are with domain integrals using a FEM solution with a refined mesh.

This paper compares different numerical methods for mode I stress intensity factor (SIF) calculations. Both 2D and 3D models are used to calculate KI for the compact tension specimens. J-integral and interaction integral provide relatively accurate results. The analysis of a reactor pressure vessel subjected to pressurized thermal shock is performed using the finite element method (FEM) and extended finite element method (XFEM). XFEM method shows advantages in modeling cracks but oscillations in 3D problems due to extraction domains for J and interaction integrals. The best results are obtained with domain integrals using a FEM with a refined mesh.