| 摘要 |
In a method of and an apparatus for detecting flaws inside articles, the flaw area for detection being subjected to ultrasonic pulses on which, after reaction with the flaw, a reference beam is superimposed, whereupon the resulting interference field is holographically detected, reconstructed and evaluated. This method can be applied to thin and sound-scattering materials with improved resolution and a description of the flaw configuration and detection of the deformation behavior of flaws. In the method, a load is applied to the flaw area under investigation and this area is subjected to ultrasonic pulses at least at two different times each corresponding to an extreme value of the loading, the ultrasonic pulses being short with respect to the load period and, after reaction with the flaw, reference pulses are superimposed on the ultrasonic pulses, whereupon the holograms of these ultrasonic applications are superimposed to give an interferogram which can be evaluated. The block schematic diagram of an apparatus for performing the method is shown in FIG. 1, in which reference 1 denotes a loading unit, 3 an ultrasonic transmitter and the units 11-5 form a control unit.
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