电弧摆动对焊接应力场的影响

Influence of arc weaving on welding residual stress field

关键词:  有限元  摆动焊接  残余应力场

Key words:  finite element model  welding with weaving  residual stresses

摘要:

摆动焊接已经广泛地应用于自动焊接过程中,以获得更高的焊接效率。在摆动焊接过程中,焊接电弧一边沿焊道长度方向运动,一边在焊道宽度方向作一定频率的摆动,这使得热源的坐标轴成"z"字形变化,从而导致摆动焊接数值模拟分析的困难。为了提高计算精度和了解电弧摆动对焊接残余应力场的影响,结合坐标变换的方法建立了摆动焊接的三维有限元模型。和无摆动焊接的残余应力结果对比表明,由于电弧摆动导致熔池附近更高的温度梯度,使得摆动焊接的横向残余应力增大,而对纵向应力场的影响较小。

Abstract:

During the automatic welding, the welding with weaving has been widely adopted as a method to improve the welding efficiency.During this process, the welding arc moves along the longitudinal path, and at the same time, weaves along the transverse path with a certain frequency.It causes that the weld center coordinates also transform in a " z" letter form, and it is very difficult to simulate this type of welding process.A conversion of coordinates is implanted in the three-dimensional finite element model in order to improve the calculation precision and comprehend the influences of the arc weaving on the residual stress fields.Comparied with the results of the welding without weaving, the results indicate that the transverse residual stresses with weaving are greater than that of the welding without weaving, while the longitudinal residual stresses are similar.The numerical results are also compared with the ones of the experiments.