Abstract
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-controlled. 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.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
