中文摘要：

在管道LBB设计和评定中,J积分和裂纹扩展稳定性的计算过程复杂,为提高计算精度和效率,需采用改进的计算方法,并实现程序软件的计算。本文基于增强参考应力法（ERS法）的J积分计算和J积分稳定性评定图法,开发LBB裂纹扩展稳定性计算程序,此程序可计算含环向穿透裂纹管道的LBB失稳载荷和临界裂纹长度。所开发的程序实现了单纯拉伸载荷、弯曲载荷及拉弯复合非比例加载下的裂纹扩展稳定性计算,并提供了两种材料真应力-真应变关系参数的输入计算方法,拓宽了现有计算方法的局限性。通过有限元计算结果和文献中管线试验结果与程序计算结果的对比分析,验证了计算程序的准确性。

英文摘要：

In LBB design and assessment of pipes , the calculations of J‐integral and crack grow th 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 sta‐bility under pure tension ,pure bending or non‐proportional combined tension and ben‐ding 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 .T he accuracy of calcu‐lation 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 .