Development of calculation program for LBB crack growth stability of pipe with circumferential through-wall crack

In LBB design and assessment of pipes, the calculations of J-integral and crack growth stability are very complicated. Hence, advanced methods need to be used and calculation programs need to be developed to enhance accuracy and efficiency of the calculations. Based on the enhanced reference stress method for J-integral estimation and J-integral stability assessment diagram method, a calculation program for LBB crack growth stability was developed. This program can evaluate the crack growth stability under pure tension, pure bending or non-proportional combined tension and bending loads. And it also offers two ways to input the material data of true stress-true strain, which broadens the application range of present methods. The accuracy of calculation in the program was verified through comparing the results with those calculated by finite element method and the test data of pipes in the literature. (authors)