Remote diagnostics of soft solids using nonlinear acoustic methods

A prototype of a new flaw detector for remote noncontact diagnostics of soft solids is proposed. The operating principle of the flaw detector is based on the features of the nonlinear interaction of two ultrasonic waves in the test material with defects. Ultrasonic waves in the test material are excited remotely by ultrasonic beams focused in air. It is demonstrated experimentally that with the help of the proposed flaw detector, subsurface defects with dimensions much smaller than the wavelength of the probing ultrasound can be remotely detected and localized.