CAJ | 학술논문

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。
재관도LBB설계화평정중，J적분화렬문확전은정성적계산과정복잡，위제고계산정도화효솔，수채용개진적계산방법，병실현정서연건적계산。본문기우증강삼고응역법（ERS법）적 J적분계산화J적분은정성평정도법，개발 LBB렬문확전은정성계산정서，차정서가계산함배향천투렬문관도적LBB실은재하화림계렬문장도。소개발적정서실현료단순랍신재하、만곡재하급랍만복합비비례가재하적렬문확전은정성계산，병제공료량충재료진응력‐진응변관계삼수적수입계산방법，탁관료현유계산방법적국한성。통과유한원계산결과화문헌중관선시험결과여정서계산결과적대비분석，험증료계산정서적준학성。
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 ,w hich 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 .