抄録
The crack growth behavior on steel compact specimens was investigated by the echo characteristic of surface wave emitted toward the end of notch under low cycle fatigue. The echo height reflected from the edge of crack and the round-trip propagation time from the surface wave probe to the edge of crack were measured for evaluating the crack growth behavior. The crack was generated from the edge of notch when the round-trip propagation time suddenly increased or the ratio of the echo height suddenly decreased. After that, The crack grew with repeating progress and stagnation alternately, and the compact specimen broke. Judging from the results of fracture surface observed by the scanning electron microscope, The fracture surface is a stripe pattern, and the distance between the lines corresponded to the part of the stagnation.
