Accession Number : ADD011345

Title :   Lightweight, Broadband Rayleigh Wave Transducer.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Moffett,M B

Report Date : 31 Jul 1984

Pagination or Media Count : 7

Abstract : A broadband angle-beam transducer system for producing and/or receiving Rayleigh waves on the surface of a metal medium comprises a thickness mode piezoelectric polymer transducer element embedded within and impedance matched to a plastic wedge. The transducer element is oriented at an angle determined to be the critical angle for Rayleigh waves in the metal structure to be tested. As a transmitter, the transducer element generates discrete dilatational wave pulses, one of which propagates within the plastic wedge to the plastic face in contact with the metal structure. At this face some of the wave energy is reflected as dilatational and shear waves within the wedge and the remainder of the wave energy passes through a coupling medium into the metal structure producing a Rayleigh wave traveling along the surface of the structure. When the system is used as a receiver, a Rayleigh wave propagating on the surface of the metal structure is received by the polymer element which then generates a voltage proportional to the Rayleigh waveform.

Descriptors :   *Patents, *Piezoelectric transducers, *Broadband transducers, *Electroacoustic transducers, Rayleigh waves, Metals, Transmitters, Receivers, Polymers, Plastics, Acoustic emissions, Acoustic detectors, Defects(Materials)

Subject Categories : Acoustic Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE