Ultrasonic pulse-echo techniques, widely used to measure the thickness of rather inaccessible structures, give poor results in the case of composite materials because of the very low working frequency. In addition, the small radiating surface, in relation to the ultrasonic wavelenght, imposes a poor directivity to the transducers which generate also a strong surface wave interfering with the bulk one. In this work we present a new technique capable to discriminate the time of arrival of the bulk wave related to the thickness information. A theoretical interpretation of this technique will be given together with a computer and an experimental simulation.
Time of arrival discrimination of interfering waves for thickness measurements in composite media
Fiorillo A. S.;
1992-01-01
Abstract
Ultrasonic pulse-echo techniques, widely used to measure the thickness of rather inaccessible structures, give poor results in the case of composite materials because of the very low working frequency. In addition, the small radiating surface, in relation to the ultrasonic wavelenght, imposes a poor directivity to the transducers which generate also a strong surface wave interfering with the bulk one. In this work we present a new technique capable to discriminate the time of arrival of the bulk wave related to the thickness information. A theoretical interpretation of this technique will be given together with a computer and an experimental simulation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
