The present study investigated the fatigue strength of the connection between longitudinal and transverse ribs using a method proposed in previous studies. Fatigue test results combined with finite element analysis and residual stress estimation confirmed that the fatigue performance of the connection can be assessed by the hot-spot stress approach and the fatigue design curve of FAT 80 (≃ JSSC E). Although the fatigue strength of the weld toes at longitudinal rib was higher than that of FAT 225, the compression residual stress, which was measured at the weld toes, was considered to affect the fatigue strength. Since the residual stresses of actual structures are hardly controlled, fatigue assessment with FAT 80 (≃ JSSC E) should be applied to the weld toes at both longitudinal and transverse ribs for safe side evaluation.

本研究使用先前研究中提出的方法研究了纵向和横向肋骨之间连接的疲劳强度。疲劳测试结果与有限元分析和残余应力估算相结合，证实可以通过热点应力方法和FAT 80（≃JSSC E）的疲劳设计曲线来评估连接的疲劳性能。尽管焊趾在纵向肋处的疲劳强度高于FAT 225，但仍认为在焊趾处测得的压缩残余应力会影响疲劳强度。由于实际结构的残余应力难以控制，因此应在纵向和横向肋骨的焊趾上使用FAT 80（≃JSSC E）进行疲劳评估，以进行安全的侧面评估。