Numerous studies have been conducted regarding the fatigue strength of longitudinal welded gusset joints. Most studies employed relatively small specimens. Thus, this study aims to evaluate the variation of fatigue life of longitudinal welded gusset joints by using the probabilistic fracture mechanics approach, particularly for larger specimens. Although some studies claimed that lower fatigue strength is found in the thicker main plate specimens, however only a limited number of fatigue test was conducted. A probabilistic approach was employed to conquer the shortfall. In this study, fatigue crack propagation analysis was performed on the main plate thicknesses of 12, 40, and 60 mm to evaluate the effect of main plate thickness on the fatigue life of the joints. Then, a probabilistic approach is given to investigate the variation of fatigue life of the joint. In addition, fatigue tests were carried out to investigate the crack propagation behavior on larger specimens. A significant decrease in fatigue life was observed by the increase of the main plate thickness from 12 to 40 mm, however, no further decrease thereafter. The fatigue strength of longitudinal welded gusset joints with the main plate thickness of 12 mm was appertained to category F in the JSSC design curve. Meanwhile, the fatigue strength of longitudinal welded gusset joints with the main plate thickness of 40 and 60 mm falls into category G in JSSC. This condition was also confirmed by the fatigue test results, where both specimens were classified as category G in JSSC.

关于纵向焊接角板接头的疲劳强度已经进行了大量研究。大多数研究采用相对较小的样本。因此，本研究旨在通过使用概率断裂力学方法来评估纵向焊接角板接头疲劳寿命的变化，特别是对于较大的样本。尽管一些研究声称较厚的主板样本疲劳强度较低，但仅进行了有限数量的疲劳试验。采用概率方法来克服这一不足。本研究对12、40和60 mm的主板厚度进行了疲劳裂纹扩展分析，以评估主板厚度对接头疲劳寿命的影响。然后，给出了概率方法来研究接头疲劳寿命的变化。此外，还进行了疲劳试验，以研究较大样本上的裂纹扩展行为。当主板厚度从 12 毫米增加到 40 毫米时，疲劳寿命显着降低，但此后不再进一步降低。JSSC设计曲线中主板厚度为12mm的纵向焊接角板节点的疲劳强度属于F类。同时，主板厚度为40和60mm的纵向焊接角板接头的疲劳强度在JSSC中属于G类。疲劳测试结果也证实了这一情况，两个样本在 JSSC 中均被归类为 G 类。