Fatigue Design Guideline for Steel Highway Bridges was issued in 2002. Requirements for standard structural details of orthotropic steel decks (OSDs) are specified to ensure the fatigue resistance. After identifying various types of fatigue cracks observed in existing OSDs, it is important to evaluate fatigue strength of present structural details and propose fatigue-resistant structural details with long-term performances. This paper discusses local stress behaviors at welded connections around cutouts between crossbeam and U-shaped rib. Analytical studies using a whole bridge model were conducted based on FEA. Effects of structural dimension of the OSDs to local stresses around the cutouts were clarified.
