Comparison of surface-wave reflection coefficients for different metals on quartz

1973 ◽  
Vol 9 (21) ◽  
pp. 495 ◽  
Author(s):  
R. Larosa ◽  
C.F. Vasile ◽  
D.V. Zagardo
Keyword(s):  
Surface Wave ◽  
Wave Reflection ◽  
Reflection Coefficients

Damage Assessment of Beams Using Flexural Wave Reflection Coefficients

2007 ◽  
Vol 347 ◽  
pp. 193-198 ◽  
Author(s):  
Simon P. Shone ◽  
Brian R. Mace ◽  
Tim P. Waters
Keyword(s):  
Damage Assessment ◽  
Wave Reflection ◽  
Experimental Results ◽  
Flexural Wave ◽  
Reflection Coefficients ◽  
Wave Power ◽  
Spring Model ◽  
Low Frequencies ◽  
Experimental Errors ◽  
Ill Conditioning

The wave reflection coefficients of damage such as cracks, notches and slots in otherwise uniform beams depend on frequency and on the size of the damage. Experimental results are presented for the wave power reflection coefficients of transverse slots of various depths sawn into a number of beam specimens. These results are compared with a conventional spring model to estimate the depth of the slot. The method appears to work well for larger slot depths (greater than about 30% of the thickness of the beam) and at higher frequencies, allowing their existence to be inferred and their size to be estimated. This is due to the fact that the reflection coefficients are larger in these regimes. For smaller slots or at low frequencies, noise and experimental errors, such as miscalibration errors and ill-conditioning, become more significant.

Fast computation of seabed spherical-wave reflection coefficients in geoacoustic inversion

2015 ◽  
Vol 138 (4) ◽  
pp. 2106-2117 ◽  
Author(s):  
Jorge E. Quijano ◽  
Stan E. Dosso ◽  
Jan Dettmer ◽  
Charles W. Holland
Keyword(s):  
Wave Reflection ◽  
Spherical Wave ◽  
Reflection Coefficients ◽  
Fast Computation ◽  
Geoacoustic Inversion

Reflection coefficients in attenuative anisotropic media

Geophysics ◽  
2009 ◽  
Vol 74 (5) ◽  
pp. WB193-WB202 ◽  
Author(s):  
Jyoti Behura ◽  
Ilya Tsvankin
Keyword(s):  
Plane Wave ◽  
Wave Reflection ◽  
Symmetry Plane ◽  
Anisotropic Media ◽  
P Wave ◽  
Substantial Contribution ◽  
Reflection Coefficients ◽  
Slowness Vector ◽  
Anisotropy Parameters ◽  
Attenuation Anisotropy

Such reservoir rocks as tar sands are characterized by significant attenuation and, in some cases, attenuation anisotropy. Most existing attenuation studies are focused on plane-wave attenuation coefficients, which determine the amplitude decay along the raypath of seismic waves. Here we study the influence of attenuation on PP- and PS-wave reflection coefficients for anisotropic media with the main emphasis on transversely isotropic models with a vertical symmetry axis (VTI). Concise analytic solutions obtained by linearizing the exact plane-wave reflection coefficients are verified by numerical modeling. To make a substantial contribution to reflection coefficients, attenuation must be strong, with the quality factor [Formula: see text] not exceeding 10. For such highly attenuative media, it is also necessary to take attenuation anisotropy into account if the magnitude of the Thomsen-styleattenuation-anisotropy parameters is relatively large. In general, the linearized reflection coefficients in attenuative media include velocity-anisotropy parameters but have almost “isotropic” dependence on attenuation. Our formalism also helps evaluate the influence of the inhomogeneity angle (the angle between the real and imaginary parts of the slowness vector) on the reflection coefficients. A nonzero inhomogeneity angle of the incident wave introduces additional terms into the PP- and PS-wave reflection coefficients, which makes conventional amplitude-variation-with-offset (AVO) analysis inadequate for strongly attenuative media. For instance, an incident P-wave with a nonzero inhomogeneity angle generates a mode-converted PS-wave at normal incidence, even if both half-spaces have a horizontal symmetry plane. The developed linearized solutions can be used in AVO inversion for highly attenuative (e.g., gas-sand and heavy-oil) reservoirs.

Surface‐wave reflection phenomena at interfaces ony‐zLiNbO3

1979 ◽  
Vol 50 (11) ◽  
pp. 6719-6728 ◽  
Author(s):  
W. S. Goruk ◽  
G. I. Stegeman
Keyword(s):  
Surface Wave ◽  
Wave Reflection
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