环焊缝打磨平台关键结构有限元分析

Finite element analysis of key structures of girth weld grinding platform

为满足油气长输管道工程施工及验收规范的要求,管道焊缝余高应在0~3 mm内,向母材平滑过渡。目前环焊缝大多依靠人工打磨,效率低且质量不稳定。现依托自动打磨系统,设计研发了环焊缝打磨平台。将角磨机转速和进给速度作为实验变量设计单因素实验,探究环焊缝打磨平台在打磨过程中所承受力的变化范围,得出法向力、轴向力和径向力的峰值为78、54、20 N。为了提高打磨平台的稳定性,采用Abaqus软件进行有限元仿真分析,对轴向进给模块的结构进行优化设计。对绕管道爬行模块的辅助轴与安装轨道接触应力进行求解,寻求安装轨道的合理壁厚。结果表明:辅助轴的增加改善了模块的应力分布,应力峰值减少6.26%,平均应力减少53.14%;轨道壁厚应不小于3.06 mm。

To meet the construction and acceptance specifications of oil and gas long-distance pipeline engineering,the residual height of the pipeline weld should be within 0~3 mm,and the transition to the base metal should be smooth.At present,girth welding is mostly done by hand,which results in low efficiency and unstable quality.Now,a girth weld grinding platform has been designed and developed based on the existing automatic grinding system.With the rotation speed and feed speed of the Angle grinder taken as experimental variables,a single-factor experiment was designed to explore the variation range of the platform´s bearing force during grinding,and the peak values of the normal force,axial force,and radial force were 78,54 and 20 N,respectively.To improve this platform´s stability,a finite element simulation analysis by Abaqus software was carried out and the structure of the axial feed module was optimized.The contact stress between the auxiliary shaft and the mounting track of the crawling module around the pipeline was solved to seek the reasonable wall thickness of the track.The results show that the stress distribution of the module is improved by adding the auxiliary shaft,with the peak stress reduced by 6.26%and the average stress reduced by 53.14%,and that the wall thickness of the track shall not be less than 3.06 mm.