OS0306 超音波後方反射強度による炭素鋼の低サイクル疲労損傷評価(OS3-2 超音波,OS-3 非破壊評価と構造モニタリング1)

抄録

Strain range controlled low-cycle fatigue tests were conducted using ultrasonic method in order to compare the state of the damage and the ultrasonic response of the STS410 and SUS316NG, and clarify the effectiveness in STS410 of this measuring method and clarify the range of frequency in which fatigue damage can be detectable using the ultrasonic back reflection. It was clarified that for the STS410 the crack growth start can be predicted according to the ultrasonic back-reflection intensity. An applicable limit in frequency is considered to exist between 20MHz and 50MHz for the present detection condition. This result can be used to predict the remaining life before the onset of crack growth within the plastic strain range used in this study and contributes the safety.