http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
高分子 PVDF 振動子를 利用한 点集束超音波探觸子의 특성
韓應敎,黃汐泰,李範成,朴俊緖,小倉幸夫 한국비파괴검사학회 1992 한국비파괴검사학회지 Vol.12 No.2
In this study, we examine the characteristics of beam and the effect of these characteristics on the flaw detection by using different type of two transducers, which are PZT and PVDF film transducer. Consequently, the detection of infinitesimal flaw is more possible than PZT, since it has beam width at focus of 60%∼65% in contrast with PZT's. Moreover we can know PVDF transducer has superiority in detecting ability for sub-suface flaw detection in view of its acoustic impedance is near to water's and its focusing range is narrower than PZT's as 65%∼85% because it has spherical surface.
톤바스트 探傷法에 의한 콘크리트의 龜裂깊이 測定에 관한 硏究
박익근,이석하,한응교,박준서 한국비파괴검사학회 1990 한국비파괴검사학회지 Vol.10 No.1
요즈음 건축물에 설치한 콘크리트의 품질, 신뢰성, 내구성, 균일성 등을 조사하기 위해서 콘크리트의 비파괴 시험에 관한 연구가 부쩍 늘고 있다. 본 논문에서는 초음파가 콘크리트속을 통과할 경우 가장 문제가 되는것은 감쇠현상인데, 이러한 감쇠를 최소한으로 줄이기 위해서 톤바스트를 이용하였다. 그 결과 균열깊이와 전파시간, 최대출력파워 스텍트럼과 출력전압, 입력주파수와 최대출력 파워스텍트럼의 상관관계는 각각 0.975, 0.847-0.718로 매우 양호함을 알았으며, 톤바스트의 잇점은 이번의 실험에서 수신파 첫동작의 경우 매우 좋았음을 알았다. Recently, research on the non-destructive testing of concrete has been rapidly increasing in relation with the quality, reliability, durability, and uniformity of concrete used in architectural structures. In this paper, the most important problem is the attenuation phenomena on throughing the side of concrete by ultrasonic wave, and applied tone-burst to decrease the attenuation in minimum. As the result, the correlation between crack-depth and propagation-time, maximum-spectrum and out-amplitude, in-frequency and maximum-spectrum are found to be excellent. The coefficient of each are +0.975, +0.847, -0.718. The merit of tome-burst through this experiment is that the start of reception wave is very excellent.