Abstract
Scatter of small fatigue crack growth rate is larger than the scatter of large fatigue crack growth rate. In fact, the transition length of small and large fatigue cracks depends on material and stress. In order to measure the transition length in specific condition, a new method using a single specimen is proposed in this study. The specimens used in this study contain eight FIB notches. Introducing eight FIB notches means that each specimen can produce eight data of fatigue crack growth rates. By using these data, the scatter of fatigue crack growth rate was evaluated, enabling the determination of the transition length. In addition, evaluation with three specimens was also conducted for validation. Finally, data of three specimens were compared to the data obtained by a specimen to verify the validity.
