Development of methods and devices for air-coupled ultrasonic through transmission testing of large-sized objects made of polymer composite materials

Abstract

It is shown that in order to increase the sensitivity of air-coupled ultrasonic through transmission testing of products made of polymer composite materials, it is necessary to develop highly sensitive low-frequency wideband air-coupled piezoelectric transducers. The methods of providing both high sensitivity and a wideband of air-coupled ultrasonic piezoelectric transducer are considered. Air-coupled ultrasonic highly sensitive broadband piezoelectric transducer based on the use of mosaic contact piezoelectric transducer technology, the choice of optimal matching layers and the use of various options for excitation of piezoelectric transmitter have been proposed and developed. It is shown that by use of mosaic air-coupled low-frequency broadband piezoelectric transducers, it is possible to ensure high sensitivity of testing and ensure the accuracy of measurement of acoustic characteristics (ultrasound velocity, density, etc.) with air-coupled ultrasonic low-frequency through transmission testing of large-sized objects made of polymer composite materials.