含内表面裂纹核级管道的初始塑性失效分析  

Initial plastic failure analysis for nuclear pipeline with internal surface crack

作　　者：李铁萍[1] 张春明[1] 马帅[1] 

机构地区：[1]环境保护部核与辐射安全中心,北京100082

出　　处：《核技术》2013年第4期135-138,共4页Nuclear Techniques

基　　金：大型先进压水堆核电站国家科技重大专项"CAP1400安全评审技术及独立验证试验"(2011ZX06002-010)资助

摘　　要：我国在役和新建的大部分核电厂在主管道上应用了破前漏技术,针对该技术ASME采用净截面屈服准则对完全塑性断裂进行缺陷评定,大量研究表明,净截面屈服准则高估了结构的承载能力。本文采用有限元方法模拟了含内表面裂纹的核级管道在内压作用下的变形过程,并利用裂纹前沿J积分随内压变化的曲线特征确定了含裂纹管道的初始塑性失效载荷。随后,将初始失效载荷的计算值与ASME规范定义的理论值相比较,结果表明理论解高估了结构的承载能力。最后,评价了ASME-BPVC-XI规范中A级使用限制对应的允许薄膜应力的适用性。Background： Leak-before-break technique is widely used in operating and abuilding nuclear plants, for which net-section-criteria is adopted by ASME to assess flawed pipes under full yielding condition. Purpose： However, net-section-criteria has been proved to overestimate the loading capacity of structure. Methods： For nuclear pipeline with internal surface crack, finite element method is used to simulate its deformation process under internal pressure, and initial plastic failure load is determined based on J integral curves of crack front. Results： Then, calculated value of initial plastic load is compared with theoretical one from ASME code, and the results show that the theoretical value overestimates the capacity load of structure. Conclusions： Finally, applicability of allowable membrance stress for level-A service restriction set by ASME-BPVC-XI code is evaluated.

关 键 词：核级管道 表面裂纹 初始塑性失效载荷 ASME-BPVC-XI规范 

分 类 号：O34[理学—固体力学]