HU Wenxiang ZHANG Shigong

(Institute of Acoustics, Tongji University Shanghai 200092)

Received Oct. 27, 2009

Revised Apr. 23, 2010

Abstract Analytical models of acoustic field excited by a pulsed-laser line source on a cylinder and a coated cylinder were presented.Surface wave dispersive behaviors for a cylinder with a slow coating were analyzed and compared with that of a bare cylinder.Based on this analysis,the laser-generated transient response of the cylindrical Rayleigh wave on cylinder and the perturbed cylindrical Rayleigh wave on coated cylinder and the higher modes were calculated from the models using residue theory and FFT technique.The theoretical results from the superposed waveform of the cylindrical Rayleigh wave and higher modes for both cylinder and coated cylinder agree well with the waveforms obtained from experiment.The transient response of perturbed Raleigh wave on coated cylinder is quite different with cylindrical Rayleigh wave on cylinder because of the guide of surface coating.The results show that the model and numerical method provide a useful technique for quantitatively characterizing coating parameters of coated cylinder by the laser generated surface waves.

PACS numbers: 43.35,43.20