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Anomalous guided waves appearing at a non-semisimple degeneracy of the fundamental matrix are observed and analyzed in the framework of the Cauchy sextic formalism. The non-semisimple degeneracy condition is explicitly constructed for the most general case of Lamb waves propagating in a traction-free layer with arbitrary elastic anisotropy. A new type of dispersion equation and the corresponding dispersion solution are obtained. The connection with surface waves of the non-Rayleigh type is discussed. [ABSTRACT FROM AUTHOR]

In this study, a modified anisotropic elastic Weiskopf model for a sandy medium was introduced, satisfying the highest rotational symmetry compatible with a Weiskopf sandiness parameter greater than the unity. The developed approach was applied for computing and comparing head SP waves propagating along the free surface of the halfspace. The comparison revealed a substantial discrepancy in the SP wave pulses detected at the points of observation. The developed models for the generation and detection of SP waves are based on the FEA (finite element analysis) of the inner Lamb problem. [ABSTRACT FROM AUTHOR]

The constructed closed form solutions for the long-wave limits for guided waves propagating in anisotropic crystals reveal a principal ability for existence of several long-wave limiting velocities exhibiting dependence on the wave normal. Numerical examples for guided waves propagating on the (1,0,0)-plane of several cubic crystals indicate existence of two distinct long-wave limiting velocities for all directions of the wave normal, except a possible discrete number of directions where two long-wave limiting velocities may coincide. [ABSTRACT FROM AUTHOR]

The closed form expressions for the low frequency velocity limits of Lamb waves propagating in anisotropic homogeneous, stratified and functionally graded (FG) plates with arbitrary elastic anisotropy and arbitrary (continuous) transverse variation of physical properties are constructed. The applied method is based on Cauchy sextic formalism coupled with the stratification convergence theorem for FG plates. The constructed solutions are obtained in the form of vanishing auxiliary determinants related to derivatives of the closed form solutions of dispersion equations. [ABSTRACT FROM AUTHOR]

Propagation of harmonic Lamb waves in plates made of functionally graded materials with transverse inhomogeneity is analyzed by applying Cauchy six-dimensional formalism previously developed for the study of Lamb wave propagation in homogeneous or stratified anisotropic plates. For anisotropic plates with arbitrary transverse inhomogeneity a closed form implicit solution for the dispersion equation is derived and analyzed. [ABSTRACT FROM AUTHOR]

A two-scale asymptotic analysis coupled with the spatially periodic fundamental solutions are used for analyzing diffraction of elastic bulk waves propagating in anisotropic media containing periodic inclusions or voids. Explicit equations are derived for the scattering cross sections and velocities of bulk waves propagating in spatially periodic media with arbitrary elastic anisotropy. [ABSTRACT FROM AUTHOR]

Propagation of Lamb waves in multilayered elastic anisotropic plates is studied in the framework of combination of the six dimensional Cauchy formalism and the transfer matrix method. The closed form secular equations for dispersion curves of Lamb waves propagating in multilayered plates with arbitrary elastic anisotropy are obtained. [ABSTRACT FROM AUTHOR]

A mathematical model for analyzing horizontally polarized shear surface (SH) waves propagating in laminated plates is presented. All the layers are assumed to have monoclinic symmetry. Three types of boundary conditions imposed on the outer surfaces of a plate are considered. A variant of the modified transfer matrix (MTM) method is developed. Closed form dispersion relations are obtained for plates consisting of one or two orthotropic layers. Asymptotic solutions for orthotropic two- and three-layered plates are derived. [ABSTRACT FROM AUTHOR]

Fundamental and singular solutions of Lamé equations for media with arbitrary elastic anisotropy are constructed on the basis of multipolar expansions (expansions in spherical harmonics) of symbols and the corresponding operators. Theorems of convergence are formulated. A posteriori error estimates are presented. [ABSTRACT FROM AUTHOR]

A mathematical model for analysis of Love waves propagating in stratified anisotropic (monoclinic) media is presented: this model is based on a newly developed Modified Transfer Matrix (MTM) method. Closed form dispersed relations are obtained for media consisting of one or two orthotropic layers lying on orthotropic substrate. Conditions for existence of Love waves are analyzed. Horizontally polarized shear surface waves of non-Love type are constructed. A numerical algorithm is worked out for obtaining dispersion relations for Love waves propagating in stratified media containing a large number of layers. [ABSTRACT FROM AUTHOR]

A six-dimensional complex formalism for analysis of Lamb waves propagating with subsonic speed in anisotropic plates is formulated. Conditions for nonexistence of certain Lam'' waves in anisotropic plates are obtained. An example of transversely isotropic plate having "forbidden" speed at which no subsonic Lamb wave propagates is presented. [ABSTRACT FROM AUTHOR]