Revealing cracks in polymer-composite parts and in multilayered glued constructions by a low-frequency acoustic method

Physical foundations for a technique of revealing cracks in laminated metal and nonmetal constructions by a low-frequency acoustic method are considered. In this technique, elastic vibrations in a product with one-sided access are excited and recorded by a double-crystal transducer when the product surface is scanned with simultaneous rotation of the transducer about its longitudinal axis. The technique allows one to improve the reliability and productivity of testing of multilayered constructions.