The service life of orthotropic steel decks is dependent on the fatigue resistance of rib‐to‐deck welded joints, which is often tested using two kinds of experimental models in terms of the rib loading condition. Different weld root fatigue failure modes have been observed in the different models, but the role of rib loading remains unclear. This paper aims to clarify the effect of rib loadings on the weld root fatigue failure modes at rib‐to‐deck welded joints. The loadings are decomposed into the deck loadings and rib loadings according to the principle of superposition. Formulae of the weld root notch stress intensity factors and T‐stress under rib loadings are developed by multiparameter regression analysis and subsequently used for the local stress analysis. The fatigue failure modes determined from the local stress field agree well with the experimental results. The results reveal that the weld root failure modes depend on the rib loadings but are independent of the weld geometries. The averaged strain energy density (SED) that can capture both weld geometry and loading condition effects is used to correlate the fatigue test data of different weld root failure modes. The SED is capable of evaluating the fatigue strength of the rib‐to‐deck welded joint failed by different weld root failure modes with a narrow scatter band.

中文翻译：

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肋对甲板焊接接头的肋骨载荷对焊根疲劳破坏模式的影响

正交异性钢甲板的使用寿命取决于肋骨到甲板的焊接接头的抗疲劳性，通常根据肋骨的载荷条件使用两种实验模型对其进行测试。在不同的模型中观察到了不同的焊缝根部疲劳破坏模式，但是肋载荷的作用仍然不清楚。本文旨在阐明肋骨载荷对肋骨到甲板焊接接头处焊缝根部疲劳破坏模式的影响。根据叠加原理，这些载荷被分解为甲板载荷和肋骨载荷。通过多参数回归分析，得出了肋骨载荷下焊缝根部缺口应力强度因子和T应力的公式，随后用于局部应力分析。由局部应力场确定的疲劳破坏模式与实验结果吻合良好。结果表明，焊缝根部破坏模式取决于肋骨载荷，但与焊缝几何形状无关。可以捕获焊接几何形状和载荷条件影响的平均应变能密度（SED）用于关联不同焊接根部失效模式的疲劳测试数据。SED能够评估由于散射带窄而导致的不同焊缝根部失效模式导致的肋骨到甲板焊接接头的疲劳强度。可以同时捕获焊缝几何形状和载荷条件影响的平均应变能密度（SED）用于关联不同焊根故障模式的疲劳测试数据。SED能够评估由于散射带窄而导致的不同焊缝根部失效模式导致的肋骨到甲板焊接接头的疲劳强度。可以捕获焊接几何形状和载荷条件影响的平均应变能密度（SED）用于关联不同焊接根部失效模式的疲劳测试数据。SED能够评估由于散射带窄而导致的不同焊缝根部失效模式导致的肋骨到甲板焊接接头的疲劳强度。