High-frequency asymptotic description of head waves and boundary layers surrounding the critical rays in an elastic half-space
- 1 September 1998
- journal article
- Published by Acoustical Society of America (ASA) in The Journal of the Acoustical Society of America
- Vol. 104 (3) , 1188-1197
- https://doi.org/10.1121/1.424327
Abstract
The high-frequency asymptotic description of head waves as well as the field inside boundary layers surrounding the critical rays are obtained for two cases: (a) a point source, and (b) a circular transducer, both acting normally on an isotropic and homogeneous elastic half-space. The edge head waves underneath a circular transducer are described by the asymptotics of a higher order compared to those of direct compressional, edge compressional, and shear waves, but are still discernible in the radiating near zone and thus might be useful in nondestructive evaluation of industrial materials. The asymptotic formulas produced involve in geometrical zones elementary functions and inside boundary layers well-known special functions. Therefore, they allow us to elucidate the physics of the problem and can be used in writing computer codes which simulate the radiating near field of a circular transducer orders of magnitude faster than full numerical schemes. The formulas have been tested against exact integral solutions evaluated numerically.This publication has 6 references indexed in Scilit:
- The radiating near-field asymptotics of a normal time-harmonic circular ultrasonic transducer in an elastic half-spaceThe Journal of the Acoustical Society of America, 1998
- The two-component representation of time-harmonic elastic body waves in the high- and intermediate-frequency regimesThe Journal of the Acoustical Society of America, 1997
- Transient ultrasonic field radiated by a circular transducer in a solid mediumThe Journal of the Acoustical Society of America, 1992
- Analysis of the transient ultrasonic fields radiated in solids by circular and annular sourcesThe Journal of the Acoustical Society of America, 1992
- The propagation of short pulses of ultrasound from a circular source coupled to an isotropic solidThe Journal of the Acoustical Society of America, 1990
- The field and radiation impedance of mechanical radiators on the free surface of a semi-infinite isotropic solidProceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1954