き裂停留現象に基づく模擬裏当て金付き突合せ溶接継手の曲げ疲労強度評価

抄録

In butt-welded joints with a backing strip, the fatigue strength is controlled by a notch (a gap between the base metal and the backing strip) at the root of the joint. The effect of the notch on the fatigue strength of welded joints depends on material properties, especially the value of the notch root radius ρ₀ at the branch point (the critical point where a nonpropagating crack appears) . In this paper, the experimental results obtained from the bending fatigue tests of simulated welded joints made by two kinds of steel are analyzed based on the characteristic fatigue behavior of standard notched specimens. The effect of reinforcement on the fatigue strength is also discussed from the same physical background.