焊接残余应力对焊接构件疲劳性能的影响

Influences of Welding Residual Stress on Fatigue Performances of Welded Components

焊接残余应力对焊接结构疲劳性能的影响是人们广泛关注的问题 ,由于影响因素复杂 ,因此 ,人们对焊接残余应力的影响产生了不同疑虑 ,也有了不同的评价。有的认为用平均应力来衡量焊接残余应力的影响 ,有的则用断裂力学中的手段来衡量 ,但它们都有着一些不可忽视的缺点。本文通过分析焊件焊缝处焊接残余应力 ,求出外载下焊缝上每一点的疲劳周次、焊件的寿命 ,从而避免了平均应力观点中平均应力的取值问题 。

The influences of welding residual stress on the performances of welded structures are the ones that arouse wide concern. Because the influential factors are complicated, there exist different doubts and opinions about the influences of the welding residual stress. Some suppose that average stress method may be used to assess the influences while some think that fracture mechanics method can be used. However, both ideas have defects that can not be neglected. In this paper, by way of analyzing the residual stress at welding joints of the welded components, the fatigue cycles at each point on the joints under external loading are obtained, and the life of the components are deviated. In this case, problem of choosing values in the average stress method is avoided. The described in the paper is quite convenient to use.