Title :
Acoustic material signature for a cracked surface
Author :
Ahn, V.S. ; Harris, J.G. ; Achenbach, J.D.
Author_Institution :
Center for Quality Eng. & Failure Prevention, Northwestern Univ., Evanston, IL, USA
Abstract :
A model of the acoustic material signature for a line-focus scanning acoustic microscope, based upon a boundary-element calculation and an electromechanical reciprocity identity, is described. The electromechanical reciprocity identity is used to relate the voltage at the terminals of the transducer of the microscope to the acoustic wavefields at the interface between the specimen and the coupling fluid. The wavefields scattered from the surface of the specimen, including the leaky Rayleigh wave, are calculated. Both a defect-free elastic surface and one broken by a crack are considered. Knowing the wavefields incident and scattered from the specimen, the acoustic signature is calculated using the reciprocity relation. Further, the results for a defect-free surface are compared with an experimental measurement
Keywords :
acoustic microscopy; boundary-elements methods; crack detection; acoustic material signature; acoustic wavefields; boundary-element calculation; coupling fluid; cracked surface; defect-free elastic surface; electromechanical reciprocity identity; interface; leaky Rayleigh wave; line-focus scanning acoustic microscope; model; reciprocity relation; specimen; terminals; transducer; voltage; Acoustic materials; Acoustic measurements; Acoustic scattering; Acoustic transducers; Acoustic waves; Microscopy; Rayleigh scattering; Surface acoustic waves; Surface cracks; Voltage;
Conference_Titel :
Ultrasonics Symposium, 1990. Proceedings., IEEE 1990
Conference_Location :
Honolulu, HI
DOI :
10.1109/ULTSYM.1990.171497
