输油管道补板焊接修复结构有限元分析

Finite Element Analysis of Plate's Welding Repair Structure in Oil Pipeline

补板修复是一种常用的输油管道焊接修复技术,焊接过程中不可避免的会产生残余应力,在应力水平较大处,管道易发生失效。基于有限元法,采用顺序耦合的方法和随温度变化的材料参数,运用有限元分析软件MSC.Marc,以管道穿孔后补板修复为例,分析了补板焊接修复过程应力、温度场的分布情况和随时间的变化规律。结果表明:冷却后补板和补板周围的残余应力最大,残余应力主要由焊接热循环引起,管道内压对残余应力的影响很小。

Patch repairing method can be seen frequently in oil pipeline welding and the residual stress is inevitable in this process and it can incur pipeline failure at the area where high stress exists. Basing on the finite element method,sequential coupling method and adopting material parameters which changing with temperatures as well as taking the patch repairing of a perforation pipe as an example,both stress field and temperature field＇s distribution in the plate＇s welding repair process and their variation with the time were analyzed to show that,the maximal residual stress locates in and near the patched plate; and the heat recycle in the welding can incur it and the pressure inside the pipeline influences the residual stress little.