이종금속 오버레이 용접 배관의 파단전누설균열 해석을 위한 단순 유한요소 모델링 방법

A Simple Finite Element Modeling Method for Leak-Before-Break Crack Analysis of Pipe with Overlay Dissimilar Metal Weldments

Several finite element models for the leak-before-break (LBB) assessment of overlay dissimilar metal weldment were constructed and analyzed to develop a simple finite element modeling method. The J-integral, crack opening displacement (COD) and J-integral distribution along the crack front in thickness direction due to the applied moment were obtained from the analysis results of the constructed finite element models, and studied compared to the previous literatures. It is concluded that the modeling with base material only is simple and produces a slightly conservative results compared to the complex modeling composed with weld metal and base metal in the calculation of J-integrals and COD values which are used for the calculation of fracture toughness and postulated leakage crack length respectively.