비파괴검사학회지 (Journal of the Korean Society for Nondestructive Testing)
- 제21권1호
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- Pages.22-31
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- 2001
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- 1225-7842(pISSN)
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- 2287-402X(eISSN)
Sensitive NDE of Small Fatigue Cracks
초록
Some techniques developed recently for sizing smalt fatigue cracks are described. One is an ultrasonic technique which deals with a small closed crack, where both the stress closing the crack and the crack size are determined by analyzing inverse problem. Here, difficulties encountered in NDE of closed cracks by usual ultrasonic techniques are summarized in advance. Secondly, the closely coupled probes potential drop (CCPPD) technique, which is based on d-c potential drop measurement, is explained fur sizing small cracks. The CCPPD technique is not affected by crack closure. Finally, a discussion is given on NDE of materials degradation in conjunction with sensitive NDE of small cracks.