SH wavefields in cylindrical double-layered elastic media excited by a shear stress source applied to a borehole wall

Autor:	J E White, Kexie Wang, Jun Ma, Gui-jin Yao
Rok vydání:	2005
Předmět:	Physics Shear waves Wave propagation Acoustics Geology Management Monitoring Policy and Law Industrial and Manufacturing Engineering Love wave symbols.namesake Geophysics Lamb waves symbols Rayleigh wave Dispersion (water waves) Mechanical wave Longitudinal wave
Zdroj:	Journal of Geophysics and Engineering. 2:169-175
ISSN:	1742-2140 1742-2132
DOI:	10.1088/1742-2132/2/2/012
Popis:	As a method of exciting shear waves in acoustic logging, the phenomenon of SH wave propagation along cylindrical double-layered elastic media surrounding a fluid-filled borehole, excited by an annular shear stress source applied to the borehole wall, is studied. The dispersion equation and excitation characteristics of guided waves and critical refracted head waves described by vertical branch cut integrals are theoretically and numerically analysed. It is found that the dispersion behaviour of guided waves as borehole radius tends to infinity is the same as that of Love waves in a half-space model with horizontally double-layered elastic media, and that the lowest-order guided waves have non-zero low cut-off frequencies. The transient full waveforms of the SH wavefield are calculated and compared with the sum of the waveforms of the component waves. Both are in good agreement.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::6491e3fe27050f9904d935bf8ba4790e https://doi.org/10.1088/1742-2132/2/2/012 Zobrazit plný text záznamu