核电箱形结构焊接变形的模拟计算与分析

Numerical Simulation oWelding Deformation in Box-like Structure of Nuclear Power Plant

传统的体积收缩法能够快速计算焊接结构的变形分布,却不能分析焊接顺序对焊接变形的影响。本文基于体积收缩法,并通过改变焊缝单元焊接前后的弹性模量来反映其刚度的变化,实现分析焊接顺序对变形影响的目的。以核电箱形结构为例,利用壳单元建立了三维计算机模型,对其中的一面侧墙装配焊焊接过程中的焊接变形进行模拟计算,并分析了焊接顺序对其焊接变形的影响。研究表明,该方法能够快速地获得不同焊接顺序下结构的变形分布情况。模拟结果显示采用分段焊会减小变形量,与理论经验吻合。

It is fast to derive deformation of the welded structures by volume shrinkage method,but it does not reflect the effect of welding sequence on the deformation.The influence of welding sequence were analyzed,based on the volume shrinkage method,the elastic modulus of the welding elements is changed before and after weld to reflect changes in its stiffness.Take a box-like structure of the nuclear power plant as an example,3D model was established by using shell elements to simulate the assembly welding deformation of a side wall of the box-like structure.The approach takes use of one-pass welding with shell element to simulate the multi-pass butt welding equivalently.By the application of this approach,the effect of welding sequence on the welding deformation was studied.The results show that the deformation distribution in different welding sequences can be obtained by this method quickly.The results show that the deformation can be reduced by the subsection welding,which is in agreement with the classic theory and experience.