一、引言由接管拐角部位发生疲劳裂纹扩展而使容器失效的现象经常见到。这是因为这些部位的结构不连续很易产生较高的应力集中,有些甚至使峰值应力达到材料屈服限的两倍以上。同时,这些部位的制造和检验都比较困难,容易形成缺陷。这种缺陷有些就已属于裂纹的范围,在使用过程中裂纹不断扩展往往导致整个 I. INTRODUCTION The phenomenon of failure of a container due to fatigue crack propagation at the corner of the takeover is often seen. This is because the structural discontinuities at these sites are prone to high stress concentrations and some even cause the peak stress to more than double the yield limit of the material. At the same time, these parts are more difficult to manufacture and test and are prone to defects. Some of these defects already belong to the scope of the crack, cracks in the use of the process of continuous expansion often leads to the whole