scholarly journals Penetration Effect: Exotic Behavior of a Wave in Anisotropic Media

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
K. Vytovtov ◽  
O. Pischin
Keyword(s):  
Wave Propagation ◽  
Anisotropic Medium ◽  
Harmonic Wave ◽  
Anisotropic Media ◽  
Ordinary Wave ◽  
Bulk Wave ◽  
Plane Harmonic Wave ◽  
Penetration Effect ◽  
Reflected Wave ◽  
First Time

Plane harmonic wave propagation along an interface between vacuum and a semi-infinite uniaxial anisotropic medium is considered. It is shown that there is a bulk wave within an anisotropic medium in this case. It is also proved for the first time that a reflected wave must propagate perpendicularly to an interface. Moreover, a reflected wave is absent in the case of ordinary wave propagation.

scholarly journals The Terahertz Controlled Duplex Isolator: Physical Grounds and Numerical Experiment

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Konstantin Vytovtov ◽  
Said Zouhdi ◽  
Rostislav Dubrovka ◽  
Volodymyr Hnatushenko
Keyword(s):  
Oblique Incidence ◽  
Faraday Effect ◽  
Harmonic Wave ◽  
Analytical Form ◽  
Electromagnetic Properties ◽  
Anisotropy Axis ◽  
Dual Frequency ◽  
Plane Harmonic Wave ◽  
Axis Orientation ◽  
First Time

Electromagnetic properties of an anisotropic stratified slab with an arbitrary orientation of the anisotropy axis under an oblique incidence of a plane harmonic wave are studied. The dependence of the eigenwave wavenumbers and the reflection coefficient on an anisotropy axis orientation and frequency is investigated. For the first time, the expression for the translation matrix is obtained in the compact analytical form. The controlled two-way dual-frequency (duplex) isolator based on the above described slab is presented for the first time. It is based on the properties of the anisotropic structure described here but not on the Faraday effect.

Plane harmonic wave propagation in three-dimensional composite media

1999 ◽  
Vol 33 (4) ◽  
pp. 263-282 ◽  
Author(s):  
Todd W. McDevitt ◽  
Gregory M. Hulbert ◽  
Noboru Kikuchi
Keyword(s):  
Wave Propagation ◽  
Harmonic Wave ◽  
Three Dimensional ◽  
Composite Media ◽  
Plane Harmonic Wave

Ultrasonic Wave Considerations for the Development of an NDE Feature Matrix for Anisotropic Media

1989 ◽  
Vol 111 (3) ◽  
pp. 255-262 ◽  
Author(s):  
J. L. Rose ◽  
A. Pilarski ◽  
K. Balasubramaniam ◽  
A. Tverdokhlebov ◽  
J. Ditri
Keyword(s):  
Wave Propagation ◽  
Longitudinal Velocity ◽  
Broad Band ◽  
Anisotropic Media ◽  
Anisotropic Elasticity ◽  
Point Of View ◽  
Experimental Point ◽  
Bulk Wave ◽  
Test Protocol ◽  
Stiffness Coefficients

The problem of ultrasonic surface and bulk wave propagation in an anisotropic media and/or a composite material is addressed so that applications in Nondestructive Evaluation can be considered, emphasis in this paper being placed on bulk wave propagation. Global material property determination is considered in an inverse wave velocity computation of stiffness coefficients based on principles of anisotropic elasticity. A one-sided inspection technique based on practical considerations of a field environment is developed. The concept of a feature matrix, based on the stiffness coefficients, is then introduced as a means of both material characterization and defect analysis in composite materials. A brief discussion on a test protocol and an interpretation of the elements in the feature matrix from an NDE point of view is also presented. The conclusions of a previous theoretical investigation of wave propagation in anisotropic media are considered from an experimental point of view by way of the bulk wave technique. A result of fundamental value is that the actual propagation of quasilongitudinal waves, generated by a standard broad band pulsed transducer, is indeed well matched with the theoretical approximation obtained earlier. This approximation was based on the generalized retarded potential principle with variable energy velocity of the quasilongitudinal mode in an anisotropic medium as the substitute for the constant longitudinal velocity used in the retarded potential scheme for an isotropic medium.

Reflection and transmission coefficients for seismic waves in ellipsoidally anisotropic media

Geophysics ◽  
1979 ◽  
Vol 44 (1) ◽  
pp. 27-38 ◽  
Author(s):  
P. F. Daley ◽  
F. Hron
Keyword(s):  
Wave Propagation ◽  
Anisotropic Medium ◽  
Transverse Isotropy ◽  
Transversely Isotropic ◽  
Anisotropic Media ◽  
Reflection And Transmission Coefficients ◽  
Reflection And Transmission ◽  
Transmission Coefficients ◽  
The Earth ◽  
Special Case

The deficiency of an isotropic model of the earth in the explanation of observed traveltime phenomena has led to the mathematical investigation of elastic wave propagation in anisotropic media. A type of anisotropy dealt with in the literature (Potsma, 1955; Cerveny and Psencik, 1972; and Vlaar, 1968) is uniaxial anisotropy or transverse isotropy. A special case of transverse isotropy which assumes the wavefronts to be ellipsoids of revolution has been used by Cholet and Richard (1954) and Richards (1960) in accounting for the observed traveltimes at Berraine in the Sahara and in the foothills of Western Canada. The kinematics of this problem have been treated in a number of papers, the most notable being Gassmann (1964). However, to appreciate fully the effect of anisotropy, the dynamics of the problem must be explored. Assuming a model of the earth consisting of plane transversely isotropic layers with the axes of anisotropy perpendicular to the interfaces, a prime requisite for obtaining amplitude distance curves or synthetic seismograms is the calculation of reflection and transmission coefficients at the interfaces. In this paper the special case of ellipsoidal anisotropy will be considered. That the quasi‐shear SV wavefront is forced to be spherical by this assumption is unfortunate, but it is instructive to investigate this simple anisotropic model as it incorporates many features inherent to wave propagation in a more general anisotropic medium. A brief outline of the theory for wave propagation in an ellipsoidally anisotropic medium is given and the analytic expressions for the reflection and transmission coefficients are listed. A complete derivation of reflection and transmission coefficients in transversely isotropic media can be found in Daley and Hron (1977). Finally, all 24 possible reflection and transmission coefficients and surface conversion coefficients are displayed for varying degrees of anisotropy.

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