DETERMINATION OF THE ELASTIC CONSTANTS OF AN ISOTROPIC SOLID USING A “PLATE” VELOCITY MEASUREMENT

From the longitudinal and shear wave velocities measured in a solid, all of its elastic constants can be determined. Jamieson and Hoskins (1963) have shown how shear wave velocities can be measured in solids with an arrangement which converts high frequency longitudinal wave pulses from axially polarized ceramic transducers into shear wave pulses. This note illustrates how such elastic constants can also be determined with the aid of longitudinal “infinite plate” velocities.

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THE MEASUREMENT OF SHEAR‐WAVE VELOCITIES IN SOLIDS USING AXIALLY POLARIZED CERAMIC TRANSDUCERS

Geophysics ◽

10.1190/1.1439152 ◽

1963 ◽

Vol 28 (1) ◽

pp. 87-90 ◽

Cited By ~ 8

Author(s):

John C. Jamieson ◽

Hartley Hoskins

Keyword(s):

Wave Propagation ◽

Shear Wave ◽

Excellent Agreement ◽

Elastic Constants ◽

Convenient Method ◽

High Frequency ◽

Critical Angle ◽

Mode Conversion ◽

Wave Velocities ◽

Shear Wave Velocities

A double mode conversion obtained by critical‐angle reflection allows the velocity of shear‐wave propagation to be determined using longitudinally polarized ceramic discs. This method provides a simple and convenient method of obtaining high‐frequency shear waves of predeterminable polarization in the laboratory. Elastic constants of brass and Pyrex obtained with this method are in excellent agreement with those measured by the PnSP method of Hughes. This mode conversion technique, unlike the PnSP method, can be used on anisotropic materials of noncylindrical geometries.

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Near-surface shear-wave velocities and quality factors derived from high-frequency surface waves

The Leading Edge ◽

10.1190/tle32060612.1 ◽

2013 ◽

Vol 32 (6) ◽

pp. 612-618 ◽

Cited By ~ 14

Author(s):

Jianghai Xia ◽

Chao Shen ◽

Yixian Xu

Keyword(s):

Surface Waves ◽

Shear Wave ◽

High Frequency ◽

Quality Factors ◽

Surface Shear ◽

Near Surface ◽

Wave Velocities ◽

Shear Wave Velocities ◽

Surface Shear Wave

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Smooth Crustal Velocity Models Cause a Depletion of High-Frequency Ground Motions on Soil in 2D Dynamic Rupture Simulations

Bulletin of the Seismological Society of America ◽

10.1785/0120200311 ◽

2021 ◽

Author(s):

Yihe Huang

Keyword(s):

Shear Wave ◽

High Frequency ◽

Ground Motions ◽

Velocity Model ◽

Dynamic Rupture ◽

Ground Acceleration ◽

Velocity Models ◽

Wave Velocities ◽

Shear Wave Velocities ◽

Crustal Velocity

ABSTRACT A depletion of high-frequency ground motions on soil sites has been observed in recent large earthquakes and is often attributed to a nonlinear soil response. Here, I show that the reduced amplitudes of high-frequency horizontal-to-vertical spectral ratios (HVSRs) on soil can also be caused by a smooth crustal velocity model with low shear-wave velocities underneath soil sites. I calculate near-fault ground motions using both 2D dynamic rupture simulations and point-source models for both rock and soil sites. The 1D velocity models used in the simulations are derived from empirical relationships between seismic wave velocities and depths in northern California. The simulations for soil sites feature lower shear-wave velocities and thus larger Poisson’s ratios at shallow depths than those for rock sites. The lower shear-wave velocities cause slower shallow rupture and smaller shallow slip, but both soil and rock simulations have similar rupture speeds and slip for the rest of the fault. However, the simulated near-fault ground motions on soil and rock sites have distinct features. Compared to ground motions on rock, horizontal ground acceleration on soil is only amplified at low frequencies, whereas vertical ground acceleration is deamplified for the whole frequency range. Thus, the HVSRs on soil exhibit a depletion of high-frequency energy. The comparison between smooth and layered velocity models demonstrates that the smoothness of the velocity model plays a critical role in the contrasting behaviors of HVSRs on soil and rock for different rupture styles and velocity profiles. The results reveal the significant role of shallow crustal velocity structure in the generation of high-frequency ground motions on soil sites.

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