Noncontact detection of surface-breaking cracks using a laser acoustic source and an electromagnetic acoustic receiver

Dewhurst, R. J.; Edwards, C.; Palmer, S. B.
August 1986
Applied Physics Letters;8/18/1986, Vol. 49 Issue 7, p374
Academic Journal
An electromagnetic acoustic transducer (EMAT) is used to detect laser generated surface acoustic transients. The surface acoustic waves are broadband and can be used to detect and size surface-breaking cracks if used in conjunction with a broadband detector. We describe a broadband EMAT and demonstrate first that it can be used to locate artificial surface-breaking defects in both aluminum and steel. A second study reveals that it can also be used for the detection of real surface-breaking cracks, even on rusty steel surfaces.


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