2024-03-29T13:24:49Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/79962020-07-16T08:31:19Zcom_10261_32com_10261_4col_10261_411
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Gómez Álvarez-Arenas, Tomás
author
Montero de Espinosa Freijo, Francisco
author
2002-09
Use of non-contact techniques to produce and sense acoustic vibrations in the
megaherzt frequency range are increasing. Higher frequencies provide higher spatial resolution while non-contact operation is an important improvement for rapid NDE scanning, analysis of materials that can not be wetted or touched, "in-situ" NDE appplications, etc. The approach we
present in this paper is based on the use of piezoelectric transducers for both signal generation and reception. It is based on the use of a stack of quarter-wavelength matching layers to improve both the efficiency and the frequency band. To this end it is extremely important to find
materials having: very low attenuation, very low acoustic impedance and the thickness requiered for the working frequency of the transducer. Piezoceramics and 1-3 connectivity piezocomposites are studied and compared. Plane and focused transducers are presented.
Forum Acusticum Sevilla 2002. Ultrasonics ; ULT-04-004-IP
84-87985-07-6
http://hdl.handle.net/10261/7996
Acoustic vibrations
Non-contact techniques
Air-coupled ultrasound
Megahertz frequency range
Nondestructive Examination (NDE)
NDE scanning
Piezoelectric transducers
Piezoelectric transducers for air-coupled operation in the frequency range 0.3-2.5 MHz