A Study on Size Effect of Fatigue Strength at Weld Joint Toe

Abstract

It is well known that fatigue strength of weld joint decreases with increasing the size of weld joint and that fatigue strength of large size girder specimens are much less than those of small joint specimens. In this study, concerning the size effect of fatigue strength, difference of stress concentration due to size and configuration of weld joint are mainly discussed. Previous fatigue test results of several types of weld joints are rearranged. According to the rearrangement, there are large differences between large scale girder specimens and small joint specimens. The difference of fatigue strength between small joint specimens can be almost evaluated by stress concentration concerning the difference of sizes of welded joints. On the other hand, difference between large scale girder specimens and small joint specimens are also affected by the presence of flange and stress condition or loading patterns.