电渣焊接头焊接残余应力与变形的数值模拟

为研究电渣焊接头焊接残余应力的分布规律及变形特征,基于有限元分析软件MSC. Marc,开发了用于模拟电渣焊接头温度场、残余应力与焊接变形的热-弹-塑性有限元计算方法. 在所开发的计算方法中,采用全椭球等密度体积移动热源模型来模拟电渣焊的热输入,并以生死单元技术考虑焊缝成形,数值模拟了箱型柱中的腹板与隔板处电渣焊接头的焊接残余应力与变形. 同时,采用试验方法实测了电渣焊接头的横向收缩及角变形. 结果表明,横向收缩和角变形的计算结果都与试验值比较吻合,验证了所开发的数值计算方法的妥当性. 此外,利用数值模拟方法详细研究了电渣焊接头焊接残余应力的分布特征.

Numerical simulation of welding residual stress and deformation induced by electro slag welding

In order to study the feature of welding residual stress distribution and distortion induced by electro slag welding (ESW), a computational approach was developed to predict welding temperature field, welding residual stress and distortion using MSC.Marc software. In the proposed approach, a new heat source named full ellipsoid volumetric heat source with uniform density was developed to model heat input produced by ESW. The "birth and death" element technique was used to simulate the formation of weld bead. The welding residual stress distribution and deformation in the box column plate and diaphragm were calculated. Meanwhile, the transverse shrinkage and angular distortion were measured by experiment. The results show that the numerical results are in a good agreement with the measured data, and the effectiveness of the computational approach was verified. In addition, the general features of welding residual stress distribution in the ESW joint was numerically investigated.