金属焊接接头疲劳寿命评价的研究

厚板焊接结构的角焊缝,多数情况下没必要完全焊透,但是,如果未焊透部分尺寸过大,就会使焊接接头的疲劳强度大幅度降低。因此,如何确定合适的坡口尺寸是十分重要的。推算疲劳寿命时,应力强度因子的定量化是很必要的,由于角焊缝十字接头的形状较复杂,所以计算应力强度因子时,不能照搬其他的计算公式。本研究用有限元法,对各种尺寸的接头情况进行计算,然后把所得的结果进行解析、整理,最后得出适用于大脚长角焊缝十字焊接接头的应力强度因子的近似计算式。

A Research about Evaluating Fatigue Life of the Metal Welding Joint

There is no need to weld the joint thoroughly for the cruciform joint. But if the dimension which is not welded is too large. that will make fatigue strength reduce. Therefore, how to decide groove dimension is very important. In estimating fatigue life of the joint, it is necessary to decide the factor of K_1 first. But we can not use nomal calculation of K_1 in cruciform joint. In this paper, I solve this problem by the FEM (Finite Element Method). After examining the result. I finally get two proximity calulatron forms for the joint which has only root crack and the jont which has only tip crack.