×

qS-waves in a vicinity of the axis of symmetry of homogeneous transversely isotropic media. (English) Zbl 1189.74062

Summary: We study propagation of the SV and SH waves, generated by a concentrated force in unbounded transversely isotropic (TI) homogeneous media acting in orthogonal to the symmetry axis direction, in a vicinity of this axis. This problem is known in geophysics as the problem of kiss singularity. Our approach is based on application of the high-frequency asymptotics of the SV and SH waves in TI media in a vicinity of the axis of symmetry. These formulas provide smooth transition of the qS-wave field from the vicinity of the axis, where the ray method fails, to the ray formulas for the SV and SH waves which are valid at some distance from the axis.
We present time pulse propagation of the coupled SV and SH waves and their splitting with the increasing distance to the symmetry axis. A distortion of the initial time pulse and evolution of the wave field polarization are discussed.

MSC:

74J10 Bulk waves in solid mechanics
74E10 Anisotropy in solid mechanics
Full Text: DOI

References:

[1] Babich, V. M., Ray method for the computation of the intensity of wave fronts in elastic inhomogeneous anisotropic medium, Problems Dyn. Theory Propagat. Seismic Waves, 5, 36-46 (1961), Leningrad University Press (in Russian) [Engl. Trans.: Geophys. J. Int. 118 (1994) 379-383].
[2] Kucherenko, V. V., Asymptotic behavior of solution of the system \(A \left``(x, - i h \frac{\partial}{\partial x}\right``) u = 0\) as \(h\)→0 in the case of characteristics of variable multiplicity, Izv. AN SSSR, Ser. Mat., 58, 2, 163-213 (1974), (in Russian)
[3] Popov, M. M.; Shchitov, I. N., On the propagation of discontinuities of a system of two interacting wave equations, Zap. Nauchn. Sem. POMI, 264, 299-310 (2000), (in Russian) [Ingl. Trans.: J. Math. Sci. 111 (5) (2002) 3799-3805] · Zbl 1028.74031
[4] Vavryčuk, V.; Yomogida, K., SH-waves Green tensor for homogeneous transversely isotropic media by higher-order approximations in asymptotic ray theory, Wave Motion, 23, 83-93 (1996) · Zbl 0911.73017
[5] Popov, M. M., SH waves in a homogeneous transversely isotropic medium generated by a concentrated force, Zap. Nauchn. Sem. POMI, 264, 285-289 (2000), (in Russian) [Engl. Trans.: J. Math. Sci. 111 (5) (2002) 3791-3798] · Zbl 1028.74030
[6] Popov, M. M.; Camerlynck, C., Second term of the ray series and validity of the ray theory, J. Geophys. Res., 101, 817-826 (1996)
[7] Chapman, C. H.; Shearer, P. M., Ray tracing in azimuthally anisotropic media-II. Quasi-shear wave coupling, Geophys. J. Int., 96, 65-83 (1989) · Zbl 0687.73030
[8] Popov, M. M., Asymptotics of the wave field in a vicinity of the axis of symmetry of a transversely isotropic homogeneous medium, Zap. Nauchn. Semin. POMI, 275, 199-211 (2001), (in Russian) [Engl. Trans.: J. Math. Sci. 117 (2) (2003) 4001-4007] · Zbl 1062.74555
[9] Musgrave, M. J.P., Crystal Acoustics (1970), Holden Day: Holden Day San Francisco · Zbl 0201.27601
[10] Buchwald, V. T., Elastic waves in anisotropic media, Proc. R. Soc. A., 252, 562-580 (1959) · Zbl 0092.42304
[11] Lighthill, M. J., Studies on magneto-hydrodynamic waves and other anisotropic wave motions, Phil. Trans. R. Soc. A., 252, 397-430 (1960) · Zbl 0097.20806
[12] Fedoryuk, M. V., The method of Steepest Descent (in Russian) (1977), Nauka: Nauka Moscow · Zbl 0463.41020
[13] Molotkov, L. A., On an inner source in transversely isotropic medium, Zap. Nauchn. Sem. POMI, 264, 238-239 (2000), (in Russian) [Engl. Trans.: J. Math. Sci. 111 (5) (2002) 3763-3769] · Zbl 1045.74031
[14] Gridin, D., Far-field asymptotics of the Green’s tensor for a transversely isotropic solid, Proc. R. Soc. Lond. A, 456, 571-591 (2000) · Zbl 0991.74042
[15] Every, A. G.; Kim, K. Y., Time domain dynamic response functions of elastically anisotropic solids, J. Acoust. Soc. Am., 95, 2505-2516 (1994)
[16] Borovikov, V. A.; Gridin, D., Kiss singularities of Green’s functions of non-strictly hyperbolic equations, Proc. R. Soc. Lond. A., 457, 1059-1077 (2001) · Zbl 0993.35006
[17] Vavryčuk, V., Properties of S waves near a kiss singularity: a comparison of exact and ray solutions, Geophys. J. Int., 138, 581-589 (1999)
[18] M.M. Popov, Ray theory and Gaussian Beam method for geophysicists, EDUFBA, Salvador, Bahia, 2002.; M.M. Popov, Ray theory and Gaussian Beam method for geophysicists, EDUFBA, Salvador, Bahia, 2002.
[19] Faria, E. L.; Stoffa, L., Finite-difference modeling in transversely isotropic media, Geophysics, 59, 2, 282-289 (1994)
[20] Payton, R. G., Symmetry axis elastic waves for transversely isotropic media, Q. Appl. Math., 35, 63-73 (1977) · Zbl 0405.73022
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.