Crack Growth Simulation Using Iterative Crack-Tip Modeling Technique

Abstract

Because of the long-term operation of nuclear power plants, the assessment of crack growth in pipelines has become one of the most important issues. Crack growth resistance in operating nuclear power plants is typically evaluated using linear elastic fracture mechanics based on ASME B&PV Section XI. However, the ASME method predicts the results conservatively, for complex shapes and conditions, while the finite element analysis, which is more accurate, consumes a substantial amount of time and cost. In this study, a finite element analysis-based iterative crack growth program was created to evaluate cracks with more accuracy and time efficiency. The verification of the program was carried out in two cases. By comparing the produced program with the test result of the three-point bending of the beam with rivet holes, it was shown that the program simulates crack propagation in the right direction. In addition, by comparing the results of the fatigue crack growth (FCG) test of CCT/SENT specimens, it was shown that the program can be applied to the evaluation of major failure mechanisms in the nuclear power plants such as stress corrosion crack (SCC) growth and FCG.