未熔透尺寸对十字焊接接头疲劳性能影响规律试验研究

针对某厂一压力机架的焊接结构，采用极大似然方法，进行了部分熔透焊接十字接头的拉—拉疲劳试验，得到了该类结构的Ｐ－Ｓ－Ｎ对数曲线。研究了未熔透尺寸对接头的应力集中系数、疲劳强度和试件疲劳破坏形式的影响规律，结果表明，在焊缝与母材等强的情况下，当未熔透尺寸２ａ／Ｔ＜０．５时，其疲劳性能无明显减弱；而当未熔透尺寸２ａ／Ｔ＞０．５时，则接头的抗疲劳性能有显著的改变。

The Effect of Non melting Depth in Welding on the Fatigue Properties of Cruciform Welded Joints

Based on fatigue test, and by using the maximum likelihood method for data processing, the effect of incomplete welding penetration on the stress concentration factor, the fatigue strength and the fatigue failure mode of some curciform welded joints are studied. The P S N curves for the joints are given. It is found that the anti fatigue property of the joints has not been substantially weakened under the condition that the non melting depth in welding 2a/T is less than 0.5, and beyond this limit, things are different.