DocumentCode :
1654939
Title :
Time of arrival discrimination of interfering waves for thickness measurements in composite media
Author :
Fiorillo, A.S. ; Lamberti, N. ; Pappalardo, M.
Author_Institution :
Dip. di Ing. dell´´Inform. e Mat. Appl., Salerno Univ., Fisciano, Italy
fYear :
1992
Firstpage :
871
Abstract :
Ultrasonic pulse-echo techniques 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. A technique based on the higher-order derivatives of the received signal, together with a proper choice of the central frequency of the driving tone burst in relation to that of the transducer, seems capable of discriminating the time of arrival of a wave masked by another. This technique can be applied in all cases in which more interfering waves are present. Only the time of arrival of the second wave (as well as that of the first one) can be detected unambiguously. A relevant role seems to be played by the phases of the higher spectral components of the received signal. A more accurate choice of the central frequency of the driving burst must be performed in order to optimize the ratio between the amplitudes of the spectral components of the received signal
Keywords :
acoustic signal processing; acoustic wave interference; composite materials; thickness measurement; time-frequency analysis; ultrasonic materials testing; US NDE; composite media; frequency domain; higher-order derivatives; inspection; interfering waves; simulation; thickness measurements; time of arrival discrimination; Composite materials; Frequency; Interference; Pulse measurements; Surface acoustic waves; Surface waves; Thickness measurement; Time measurement; Transducers; Ultrasonic variables measurement;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Ultrasonics Symposium, 1992. Proceedings., IEEE 1992
Conference_Location :
Tucson, AZ
Print_ISBN :
0-7803-0562-0
Type :
conf
DOI :
10.1109/ULTSYM.1992.275859
Filename :
275859
Link To Document :
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