抄録
Initiating mechanism for fatigue cracks which initiated from the root of welded joints between deck plates and U-ribs and propagated toward the surface of the weld bead (bead-through cracks) has not been clarified yet. In previous study, bead-through cracks have been initiated by wheel load running test using large-scale specimen. In this study, the parts which had bead-through cracks initiated from the weld root and appeared to the surface of the weld bead have been cut away. Then, the bead-though crack origin was observed by macroscopic test. In addition, 3D FEA have been performed paying attention to weld root of specimens. As a result, when depth of weld penetration is small, bead-through cracks are easy to occur.
