燃气管道焊接修复残余应力的有限元分析

Finite element analysis of residual stress of welding repair for gas pipeline

运用大型有限元分析软件ABAQUS的热-力耦合功能,对20钢燃气管道全补焊和局部补焊修复方式进行有限元模拟,获得了这两种修复方式焊接接头的残余应力分布情况。同时对内压与焊接残余应力共同作用下的补焊接头进行有限元分析。结果表明,采用全补焊方法修复后的燃气管道焊接接头残余应力明显小于局部补焊;而且在内压与焊接残余应力共同作用下,全补焊接头有较低的拉应力。这说明全补焊接头的承载性能更好,同时降低了燃气管道应力腐蚀开裂的可能性,适合工程应用。研究结果为优化燃气管道焊接修复工艺提供了理论基础。

By the finite element analysis software ABAQUS and the function of coupling process between heat and stress, the methods of entirety welding repair and local welding repair were simulated for 20-steel gas pipeline, and the distributions of the two kinds of welding residual stress were obtained. At the same time, the stress of welding-repair joint was analyzed by ABAQUS under inner pressure and welding residual stress. The results indicate that the residual stress of the entirety welding repair is lower than that of the local welding repair. And under inner pressure and welding residual stress, the teasile stress of the entirety welding repair is lower than that of the local welding repair too. It shows that the entirety welding repair joint is stronger than the local welding repair joint. The method of the entirety welding repair can reduce the probability of stress corrosion cracking and fit for the engineering application. The research results provide theory base for optimizing welding repair technology.