A sensitive ultrasonic approach to NDE of tightly closed small cracks
A sensitive ultrasonic approach to NDE of tightly closed small cracks
复制标题
一种敏感的超声波方法对紧密闭合的小裂纹进行无损检测
DOI：
10.1115/1.2842348
复制
发表时间：
1998
影响因子：
1
通讯作者：
M. Saka
中科院分区：
文献类型：
--
作者：
S. R. Ahmed;M. Saka
发展了一种灵敏的超声技术，用于对闭合小裂纹进行定量无损评价。强调了在试样表面上具有小入射角的斜向纵波的使用。首先对张开型裂纹进行超声检测，以预测最佳评价角度，然后推导出评价角度的经验校准方程，作为处理闭合型裂纹分析的依据。通过对真实的疲劳裂纹的测量，通过分析反问题，同时确定了有关参数，特别是裂纹尺寸和闭合应力。评估结果被认为是在良好的符合破坏性的测量，并实现了相应的优越性的方法，特别是对于紧密闭合的小疲劳裂纹，当与方法相比，使用一束纵波入射正常和/或与一个大的角度。
A sensitive ultrasonic technique for the quantitative nondestructive evaluation of small closed cracks is developed. The use of an oblique longitudinal wave with small angle of incidence upon the specimen surface is emphasized. Firstly, ultrasonic testing is performed with open cracks in order to predict the optimum angle of evaluation, and an empirical calibration equation is then derived for the same as a basis to deal with the analysis of closed cracks. From the measurement on real fatigue cracks, the parameters of interest, specifically the crack size and the closure stress, are determined simultaneously by analyzing the inverse problem The method developed here is fully automated and computer-controuea. Evaluated results are found to be in good conformity with the destructive measurements, and the corresponding superiority of the method is realized, especially for tightly closed small fatigue cracks, when compared with the method using a beam of longitudinal wave incident normally and/or with a large angle.