Shear horizontal surface acoustic waves in functionally graded magneto-electro-elastic half-space

2015 ◽  
Vol 97 (1) ◽  
pp. 83-100 ◽  
Author(s):  
H. M. Shodja ◽  
S. Eskandari ◽  
M. Eskandari
Keyword(s):  
Half Space ◽  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Elastic Half Space ◽  
Functionally Graded ◽  
Horizontal Surface ◽  
Shear Horizontal

Shear Horizontal Surface Waves in a Functionally Graded Magneto-Electro-Elastic Half-Space

2011 ◽  
Vol 304 ◽  
pp. 204-207
Author(s):  
Qian Yang ◽  
Yan Ping Kong ◽  
Jin Xi Liu
Keyword(s):  
Free Surface ◽  
Boundary Conditions ◽  
Surface Waves ◽  
Half Space ◽  
Material Properties ◽  
Elastic Half Space ◽  
Functionally Graded ◽  
Horizontal Surface ◽  
Propagation Characteristics ◽  
Shear Horizontal

We investigate the propagation of shear horizontal (SH) surface waves in a functionally graded magneto-electro-elastic half-space with hexagonal (6mm) symmetry. The material properties vary in the direction perpendicular to the free surface. The surface of the half-space is mechanically free, but subjected to four types of electromagnetic boundary conditions. These boundary conditions are electrically open/magnetically closed, electrically open/magnetically open, electrically closed/magnetically open and electrically closed/magnetically closed. The effects of the electromagnetic boundary conditions and the variation of material properties on the propagation characteristics of SH surface waves are analyzed. The results obtained show that except for the electrically open/magnetically closed condition, three sets of other electromagnetic boundary conditions sustain the propagation of SH surface waves. Different from the case in homogeneous materials, the existing SH surface waves in functionally graded half-spaces are dispersive.

Existence and spectral properties of shear horizontal surface acoustic waves in vertically periodic half-spaces

2009 ◽  
Vol 465 (2105) ◽  
pp. 1489-1511 ◽  
Author(s):  
A.L. Shuvalov ◽  
O. Poncelet ◽  
S.V. Golkin
Keyword(s):  
Material Properties ◽  
Acoustic Waves ◽  
Spectral Properties ◽  
Surface Acoustic Waves ◽  
Homogeneous Boundary Condition ◽  
Horizontal Surface ◽  
Infinite Strip ◽  
Discrete Variation ◽  
Time Space ◽  
Shear Horizontal

The paper is concerned with the propagation of shear horizontal surface waves (SHSW) in semi-infinite elastic media with vertically periodic continuous and/or discrete variation of material properties. The existence and spectral properties of the SHSW are shown to be intimately related to the shape of the properties variation profile. Generally, the SHSW dispersion branches represent randomly broken spectral intervals on the ( ω ,  k ) plane. They may, however, display a particular regularity in being confined to certain distinct ranges of slowness s = ω / k , which can be predicted and estimated directly from the profile shape. The SHSW spectral regularity is especially prominent when the material properties at the opposite edge points of a period are different. In particular, a unit cell can be arranged so that the SHSW exists within a single slowness window, narrow in the measure of material contrast between the edges, and does not exist elsewhere or vice versa. Explicit analysis in the ( ω ,  k ) domain is complemented and verified through the numerical simulation of the SH wave field in the time–space domain. The results also apply to a longitudinally periodic semi-infinite strip with a homogeneous boundary condition at the faces.

Shear horizontal surface acoustic waves in a magneto-electro-elastic system

2016 ◽  
Vol 25 (1-2) ◽  
pp. 1-13 ◽  
Author(s):  
Shahin Eskandari ◽  
Hossein M. Shodja
Keyword(s):  
Power Series ◽  
Shear Wave ◽  
Half Space ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Acoustic Waves ◽  
Series Solution ◽  
Surface Acoustic Waves ◽  
Power Series Solution ◽  
Shear Horizontal

AbstractPropagation of shear horizontal surface acoustic waves (SHSAWs) within a functionally graded magneto-electro-elastic (FGMEE) half-space was previously presented (Shodja HM, Eskandari S, Eskandari M. J. Eng. Math. 2015, 1–18) In contrast, the current paper considers propagation of SHSAWs in a medium consisting of an FGMEE layer perfectly bonded to a homogeneous MEE substrate. When the FGMEE layer is described by some special inhomogeneity functions – all the MEE properties have the same variation in depth which may or may not be identical to that of the density – we obtain the exact closed-form solution for the MEE fields. Additionally, certain special inhomogeneity functions with monotonically decreasing bulk shear wave velocity in depth are considered, and the associated boundary value problem is solved using power series solution. This problem in the limit as the layer thickness goes to infinity collapses to an FGMEE half-space with decreasing bulk shear wave velocity in depth. It is shown that in such a medium SHSAW does not propagate. Using power series solution we can afford to consider some FGMEE layers of practical importance, where the composition of the MEE obeys a prescribed volume fraction variation. The dispersive behavior of SHSAWs in the presence of such layers is also examined.

Monitoring Polymer Properties Using Shear Horizontal Surface Acoustic Waves

2009 ◽  
Vol 1 (10) ◽  
pp. 2382-2389 ◽  
Author(s):  
Dana Y. Gallimore ◽  
Paul J. Millard ◽  
Mauricio Pereira da Cunha
Keyword(s):  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Horizontal Surface ◽  
Polymer Properties ◽  
Shear Horizontal
Sign in / Sign up

Export Citation Format

Share Document