NONLINEAR ULTRASONIC METHOD AND DEVICE FOR DETECTING CRACKSAND THEIR LOCATIONS IN SOLID BODY Russian patent published in 2006 - IPC G01N29/04 

FIELD: detection of cracks.

SUBSTANCE: ultrasonic pulses sequence with frequency F of sending is irradiated into solid body. Modulation of cracks is performed by periodical sequence of single acoustic pulses which create sequence of propagating acoustic pulses of compression and rarefaction, which sequence changes according to specific law with period of T. Delay in radiation of acoustic pulses is preset which delay provides coincidence in the area of analysis of ultrasonic pulses and maximal values of amplitudes of acoustic pulses and harmonic is determined in spectral composition of received ultrasonic pulses in selected areas. The harmonic should correspond to preset period of repetition of acoustic pulses. Amplitude of sequence of pulses is used to determine cracks availability factor k. When factor k exceeds threshold value determined on the base of measurements of defect-free solid body, sizes of cracks are reported.

EFFECT: widened area of solid bodies being available for inspection.

8 cl, 3 dwg