| 摘要 |
FIELD: nondestructive testing; ultrasonic testing. ^ SUBSTANCE: to detect signal reflected from a defect and to estimate location of defect, information properties of signal are analyzed at output of receiver of flaw detector by means of large-scale wavelet testing methodology which allows to find small in amplitude local changes of signal including "dead zone" of flaw detector. Wavelet-spectrograms of reference signal are formed at output of receiving path of flaw detector which corresponds to case when defect is absent in tested sample. When defect of unknown quality appears in tested material, wavelet-spectrogram of controlled signal at output of receiving path of flaw detector Wf (a, t) and its ai cross-section at different scales of ai would differ from wavelet-spectrogram of reference signal which is adequate to detection of signal reflected from defect. To find the location of defect the wavelet-spectrograms of shortened realizations of reference and controlled signals are formed sequentially for time of tauy. Shortening of signals is performed from the end of sequence for the same value till wavelet-spectrograms of shortened realizations of reference and controlled signals as well as their cross-sections become practically equal at different scales of ai. Length of those shortened realizations of reference and controlled signals has to be evaluation of defect location. ^ EFFECT: improved precision. ^ 2 cl, 11 dwg |
