원자력 배관의 피로 및 응력부식결함성장 해석을 위한 확장유한요소법의 적용성 검증

Validation of Extended Finite Element Method for Fatigue and Stress Corrosion Crack Growth Analysis in Nuclear Piping

This study investigates the application of the extended finite element method (xFEM) for fatigue and stress corrosion crack growth analysis in nuclear piping. Stress corrosion crack growth analysis was performed using xFEM considering various element size ratio. The results are compared with ASME Section XI procedures and the AI-FEM program. An appropriate element size ratio was presented through the comparison of crack growth results. The proposed element size ratio was validated in the context of piping fatigue crack growth. The xFEM results applying the proposed element size criteria showed good agreement with ASME Section XI and AI-FEM for both stress corrosion and fatigue crack growth. Additionally, the applicability of xFEM to complex crack shapes is demonstrated through comparison with AI-FEM results. The study concludes that xFEM can effectively simulate crack growth in nuclear piping with various thicknesses, crack geometries, and loading conditions when using the proposed modeling criterion. This research contributes to enhancing the applicability of xFEM in flaw evaluations for nuclear piping, providing an alternative to traditional finite element methods and code-based procedures.