초음파진행 시간차에 의한 STUD[BOLT] 나사산의 미세한 결함검출

Ultrasonic Detection of Small Crack in Studs[Bolts] by Time Difference of Thread Signals(TDTS)

It is difficult to detect such flaws as stress - corrosion cracking or corrosion wastage(loss of bolt diameter) in the threads. In many cases the critical size of a flaw is very small(1-2 mm order). This paper describes how it is possible to discriminate small flaw indications in threads using the time difference or thread signals(TDTS) by a signal-conditioning technique.