OS0736 荷重非伝達型十字すみ肉溶接継手における疲労き裂進展挙動の考察(構造用材料の疲労挙動と寿命評価,オーガナイズドセッション)

抄録

Metal fatigue processes are divided into two main categories. One is a crack initiating process, and the other is a crack propagation process. Since the crack propagation life dominates a larger portion of the fatigue life in large-sized structures, it becomes more important to evaluate the propagation process accurately. In this study, the crack propagation behavior on a non-load-carrying cruciform welded joint is observed by a beach mark method to obtain basic data for crack propagation simulation. The observation result showed that adjacent cracks merged at an earlier stage of a fatigue test in the shorter life region. This means the crack under such a stress field can be treated as a single-edge crack. In contrast, a crack propagates independently in the longer life region. The border life was approximately 5.5x10^5 cycles.