The rib-to-deck welded joints in orthotropic steel decks (OSDs) are prone to fatigue damage with different fatigue failure modes. The damage accumulation of the corresponding failure modes should be estimated in repair design. This study proposed a unified fatigue life evaluation method for different failure modes of rib-to-deck welded joints based on the structural stress method and linear damage accumulation theory. The method considers the effect of crack depth and crack propagation on life evaluation, validated by the tests of repaired rib-to-deck joints with interior repair welds. Damage accumulation before and after repairing corresponding to different failure modes was assessed. The dominant failure modes before and after repairing were analyzed. Finally, the damage accumulation law of welded joints after repair under standard traffic load was investigated based on the existing damage status of each failure mode of the rib-to-deck welded joint. The results indicate that the failure mode will transfer from root-deck to exterior toe-deck at the rib-to-deck joint after the interior repair welding. The dominant failure mode of the repaired joint is governed by the existing damage status and the repair method.

正交各向异性钢甲板 (OSD) 中肋板与甲板的焊接接头容易发生疲劳损伤，疲劳失效模式各不相同。维修设计时应估计相应失效模式的损伤累积。该研究提出了一种基于结构应力法和线性损伤累积理论的肋板-甲板焊接接头不同失效模式的统一疲劳寿命评估方法。该方法考虑了裂纹深度和裂纹扩展对寿命评估的影响，并通过带有内部修复焊缝的修复后的肋材与甲板接头的测试进行了验证。评估修复前后不同失效模式对应的损伤累积。分析了修复前后的主要失效模式。最后，基于肋板-甲板焊接接头各失效模式存在的损伤状态，研究了标准交通荷载下修复后焊接接头的损伤累积规律。结果表明，内部补焊后，失效模式将在肋板与甲板连接处从根部甲板转移到外部趾板。修复接头的主要失效模式由现有的损坏状态和修复方法决定。