INFLUENCE OF EMBEDDED DEFECTS ON FATIGUE PERFORMANCE OF BUTT-WELDED JOINTS AND A TRIAL OF DEMAND QUALITY LEVELS

Abstract

As recent tendency of steel highway bridge consturction, 2 or 3 main girder bridges have been constructed. Flange plates of those bridges are welded as butt-welded joints at site. Fatigue resistance of those joints are considered sensitive to inside weld defects. It is important to clarify the weld quality requirements for evaluating NDT results. Fatigue tests of butt-welded joints with various sizes/types of intentionally embeded defects were carried out in order to clarify their influence on fatigue resistance. Based on the results, allowable defect size for butt-welded joints were proposed.