TY - JOUR
T1 - New ultrasonic angle-beam technique for sensitive evaluation of closed cracks
AU - Ahmed, S. R.
AU - Saka, M.
N1 - Funding Information:
The authors would like to acknowledge President H. Abé of Tohoku University for his valuable suggestions throughout this study. Thanks are also due to Mr. M. Mikami for his technical assistance in preparing the specimens. This study was partly supported by The Ministry of Education, Science, Sports and Culture under Grant-in-Aid for Scientific Research (B) (2) 10450042.
PY - 2000/6/1
Y1 - 2000/6/1
N2 - This paper is on the ultrasonic nondestructive evaluation of smaller cracks in the size range of 1-7 mm. Sensitive evaluation of the crack that was originally present or that developed during operation is imperative for assessing the integrity of structural components. In order to develop a method for the enhancement of sensitivity of ultrasonic evaluation of closed cracks, the principle of a new angle-beam approach is proposed, where the use of an oblique longitudinal wave with a small angle of incidence upon the specimen surface is emphasized. The crack treated exists nearly vertically on the back surface of the specimen. In contrast with the normally incident wave beam, the effect of angular incidence on the ultrasonic response due to a crack is investigated in an attempt to predict the optimum angle of evaluation. The sensitive feature of the present angle-beam technique is discussed in light of comparison made with the usual methods of normal incidence and large-angle beam technique. Ultrasonic measurements performed on the closed fatigue-cracked specimens show that the method offers bright prospects for the sensitive evaluation of small, closed cracks.
AB - This paper is on the ultrasonic nondestructive evaluation of smaller cracks in the size range of 1-7 mm. Sensitive evaluation of the crack that was originally present or that developed during operation is imperative for assessing the integrity of structural components. In order to develop a method for the enhancement of sensitivity of ultrasonic evaluation of closed cracks, the principle of a new angle-beam approach is proposed, where the use of an oblique longitudinal wave with a small angle of incidence upon the specimen surface is emphasized. The crack treated exists nearly vertically on the back surface of the specimen. In contrast with the normally incident wave beam, the effect of angular incidence on the ultrasonic response due to a crack is investigated in an attempt to predict the optimum angle of evaluation. The sensitive feature of the present angle-beam technique is discussed in light of comparison made with the usual methods of normal incidence and large-angle beam technique. Ultrasonic measurements performed on the closed fatigue-cracked specimens show that the method offers bright prospects for the sensitive evaluation of small, closed cracks.
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U2 - 10.1016/S0963-8695(99)00049-3
DO - 10.1016/S0963-8695(99)00049-3
M3 - Article
AN - SCOPUS:0033907364
VL - 33
SP - 261
EP - 271
JO - NDT and E International
JF - NDT and E International
SN - 0963-8695
IS - 4
ER -