疲労き裂の板厚貫通挙動とその寸法効果

抄録

Fatigue life and crack through-thickness behavior was examined experimentally by using a large and small specimen. The material uesd was HT80 steel. The fatigue crack shape before through-thickness is almost semicircular, and the measured aspect ratio is larger than the value obtained by calculation using the K value proposed by Newman-Raju. It is found that the crack growth behavior on the back side after through-thickness is unique regardless of the specimen size and can be divided into three stages a, b and c. By using the K value proposed by the authors, remarkable crack growth behavior and the change in crack shape can be evaluated quantitatively. And also crack opening displacement can be evaluated quantitatively by using the model proposed by the authors.