摘要
管道环焊缝的实际低强匹配是引发焊缝断裂失效的重要原因,在焊缝的适用性评估中,失效评估图方法无法准确考虑焊缝强度匹配的影响,准确纳入强度匹配成为拓宽失效评估图方法应用于高钢级管道环焊缝裂纹缺陷评估的关键。基于非线性有限元法,建立了高钢级管道环焊缝裂纹驱动力的数值仿真模型,采用等效应力应变关系方法构建了环焊缝裂纹的通用失效评估曲线,采用裂纹驱动力的有限元计算结果,结合BS 7910-2019《金属结构中缺陷可接受性评估方法指南》推荐方法,构建了系列不同载荷水平下的有限元评估点,探明了BS 7910-2019对于环焊缝裂纹缺陷的评估精度,查明了影响评估结果精度的关键原因。在此基础上,考虑裂纹深度、裂纹长度、焊缝强度匹配系数,提出了优化的管道环焊缝极限载荷计算模型以及改进的失效评估图方法,准确将焊缝强度匹配纳入到失效评估图方法中,进一步提高了高钢级管道环焊缝裂纹缺陷的评估精度,可为在役高钢级管道环焊缝裂纹的适用性评估提供参考。(图11,参24)
The actual strength under-matching of pipeline girth welds is a principal cause for the fracture failure of welds.The current Failure Assessment Diagram(FAD)method for the applicability assessment of pipeline welds cannot accurately consider the influence of weld strength matching.Thus,accurate inclusion of strength matching becomes critical to broaden the FAD method to apply to the crack defect assessment for the girth welds of high-grade steel pipelines.Based on the nonlinear finite element method,a numerical simulation model of the crack driving forces for the girth welds of high-grade steel pipelines was established,and the general failure assessment curve of girth weld cracks was plotted with the equivalent stress-strain relationship method.Then,a series of finite element assessment points under different load levels were determined with the finite element calculation results of the crack driving forces in combination with the recommended methods in Guide to methods for assessing the acceptability of flaws in metallic structures(BS 7910-2019).Further,the assessment accuracy of BS 7910-2019 to the crack defects of girth welds was determined,and the critical causes affecting the accuracy of the assessment results were investigated.On this basis,the optimized ultimate load calculation model of the pipeline girth welds and the improved FAD method were put forward with the crack depth,the crack length and the weld strength matching coefficient considered,and the weld strength matching was accurately included into the FAD method.Thereby,the assessment accuracy of the girth weld crack defects of the high-grade steel pipelines was further enhanced.Generally,the method could provide reference for the applicability assessment of the girth weld cracks of in-service high-grade steel pipelines.(11 Figures,24 References)
作者
吴锴
张宏
杨悦
刘啸奔
隋永莉
陈朋超
WU Kai;ZHANG Hong;YANG Yue;LIU Xiaoben;SUI Yongli;CHEN Pengchao(China University of Petroleum(Beijing)//National Engineering Laboratory for Pipeline Safety//MOE Key Laboratory of Petroleum Engineering//Beijing Key Laboratory of Urban Oil and Gas Distribution Technology;China Petroleum Pipeline Research Institute Co.Ltd.;PipeChina North Pipeline Company)
出处
《油气储运》
CAS
北大核心
2021年第9期1008-1016,共9页
Oil & Gas Storage and Transportation
基金
国家自然科学基金资助项目“逆断层作用下X80管道屈曲演化与韧性破损机理研究”,52004314
新疆自治区天山青年计划项目“复杂载荷作用下高钢级管道韧性断裂与后屈曲失效行为”,2019Q088。
关键词
环焊缝
高钢级
强度匹配
失效评估图
断裂评估
girth welds
high-grade
strength matching
Failure Assessment Diagram(FAD)
fracture assessment
