Influence of Poisson's Ratio on Surface Wave Near-Field Effects

2011 ◽  
Author(s):  
Brent L. Rosenblad ◽  
Cheng-Hsuan Li
Keyword(s):  
Surface Wave ◽  
Poisson’S Ratio ◽  
Near Field ◽  
Poisson's Ratio ◽  
Field Effects

Surface-wave dispersion in Byrd Land, Antarctica

1972 ◽  
Vol 62 (4) ◽  
pp. 955-959 ◽  
Author(s):  
H. K. Acharya
Keyword(s):  
Surface Wave ◽  
Ultrasonic Velocity ◽  
Poisson’S Ratio ◽  
Wave Dispersion ◽  
Poisson's Ratio ◽  
Constant Density ◽  
Velocity Measurements ◽  
Land Area ◽  
Surface Wave Dispersion ◽  
Ice Cap

Abstract Assuming constant density and Poisson's ratio of 0.25, theoretical surface-wave dispersion has been computed for the Byrd Land area in Antarctica, where the velocity increases monotonically with depth. Comparison with observed dispersion indicates 8 to 10 per cent anisotropy in the ice cap. Such anisotropy was also detected from ultrasonic velocity measurements on snow cores.

The azimuthal and polar radiation patterns obtained from a horizontal stress applied at the surface of an elastic half space

1962 ◽  
Vol 52 (1) ◽  
pp. 27-36
Author(s):  
J. T. Cherry
Keyword(s):  
Surface Wave ◽  
Half Space ◽  
Rayleigh Waves ◽  
Poisson’S Ratio ◽  
Horizontal Stress ◽  
Elastic Half Space ◽  
The Body ◽  
Body Waves ◽  
Poisson's Ratio ◽  
A Value

Abstract The body waves and surface waves radiating from a horizontal stress applied at the free surface of an elastic half space are obtained. The SV wave suffers a phase shift of π at 45 degrees from the vertical. Also, a surface wave that is SH in character but travels with the Rayleigh velocity is shown to exist. This surface wave attenuates as r−3/2. For a value of Poisson's ratio of 0.25 or 0.33, the amplitude of the Rayleigh waves from a horizontal source should be smaller than the amplitude of the Rayleigh waves from a vertical source. The ratio of vertical to horizontal amplitude for the Rayleigh waves from the horizontal source is the same as the corresponding ratio for the vertical source for all values of Poisson's ratio.

REFLECTION OF AN ACOUSTICAL PRESSURE PULSE FROM A LIQUID‐SOLID PLANE BOUNDARY

Geophysics ◽  
1956 ◽  
Vol 21 (1) ◽  
pp. 71-87 ◽  
Author(s):  
T. W. Spencer
Keyword(s):  
Surface Wave ◽  
Poisson’S Ratio ◽  
Velocity Ratio ◽  
Elastic Solid ◽  
Vertical Axis ◽  
Vertical Displacement ◽  
Poisson's Ratio ◽  
Plane Boundary ◽  
The Laplace Transform ◽  
Compressional Velocity

The problem treated is concerned with predicting the transient response of a system composed of a liquid layer, bounded above by a vacuum and below by a perfectly elastic solid, when excited by an arbitrary pressure applied uniformly over the surface of a spherical cavity located in the fluid. The Laplace transform of the displacement response is expressed in terms of an integral which is expanded in such a way that each term describes the contribution from one of the image sources. Each term may be evaluated exactly at points located on a vertical axis passing through the source. The final expression for the vertical displacement at axial points is composed of the acoustic, after‐flow, and correction terms. In solids for which Poisson’s ratio is greater than one third the initial variation of the correction is toward positive values (corresponding to motion directed toward the interface). For Poisson’s ratio less than one third the initial variation may be either positive or negative depending on the magnitude of the compressional velocity ratio. A surface wave is shown to exist regardless of the choice of parameters. The surface wave velocity is always less than it would be in the absence of the liquid.

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