This paper presents experimental and numerical analysis results regarding the effects of an incomplete penetration defect on the fatigue lives of socket welded pipes. For the experiment, four-point bending fatigue tests with various defect geometries (defect depth and circumferential length) were performed, and test results are presented in terms of stress-life data. The results showed that for circumferentially short defects, the fatigue life tends to increase with increasing crack depth, but for longer defects, the trend becomes the opposite. Finite element analysis showed that for short defects, the maximum principal stress decreases with increases in crack depth. For a longer defect, the opposite trend was found. Furthermore, the maximum principal stress tends to increase with an increase in defect length regardless of the defect depth.

本文介绍了关于未焊透缺陷对承插焊管疲劳寿命影响的实验和数值分析结果。在实验中，进行了具有各种缺陷几何形状（缺陷深度和圆周长度）的四点弯曲疲劳试验，并以应力-寿命数据形式呈现了试验结果。结果表明，对于周向较短的缺陷，疲劳寿命往往随着裂纹深度的增加而增加，但对于较长的缺陷，趋势相反。有限元分析表明，对于短缺陷，最大主应力随着裂纹深度的增加而减小。对于较长的缺陷，发现了相反的趋势。此外，无论缺陷深度如何，最大主应力都会随着缺陷长度的增加而增加。