Inversion for the complex elastic modulus of material from spherical wave propagation data in free field

2019 ◽  
Vol 459 ◽  
pp. 114851
Author(s):  
Qiang Lu ◽  
Zhan-jiang Wang ◽  
Yang Ding
Keyword(s):  
Wave Propagation ◽  
Elastic Modulus ◽  
Free Field ◽  
Spherical Wave

Spherical Wave Propagation Through a Random Continuum

Radio Science ◽  
1967 ◽  
Vol 2 (12) ◽  
pp. 1513-1515 ◽  
Author(s):  
D. A. deWolf
Keyword(s):  
Wave Propagation ◽  
Spherical Wave

scholarly journals Separating the scattered wavefield from teleseismic P using curvelets on the long beach array data set

2019 ◽  
Vol 220 (2) ◽  
pp. 1112-1127
Author(s):  
Jia Zhang ◽  
Charles A Langston
Keyword(s):  
Wave Propagation ◽  
Signal To Noise Ratio ◽  
Spherical Wave ◽  
Curvelet Transform ◽  
Structural Heterogeneity ◽  
Seismic Array ◽  
P Wave ◽  
Long Beach ◽  
Data Set ◽  
Array Data

SUMMARY A dense seismic array, composed of over 5000 stations with an average spacing close to 120 m was deployed in Long Beach, CA, by NodalSeismic and Signal Hill Petroleum as part of a survey associated with the Long Beach oilfield. Among many interesting wave propagation effects that have been reported by others, we observe that the coda of teleseismic P waves display waves caused by obvious local scattering from the Signal Hill popup structure between strands of the Newport-Inglewood fault. The density of the seismic array allows space-based methods, such as the Curvelet transform, to be investigated to separate the teleseismic and local scattered wavefields. We decompose a synthetic wavefield composed of a teleseismic plane wave and local scattered spherical wave in the curvelet domain to test the plausibility of our curvelet analysis and then apply the technique to the Long Beach array data set. Background noise is removed by a soft thresholding method and a declustering technique is applied to separate the teleseismic and local scattered wavefield in the curvelet domain. Decomposed results illustrate that the signal-to-noise ratio of the teleseismic P wave can be significantly improved by curvelet analysis. The scattered wavefield is composed of locally propagating Rayleigh waves from the pop-up structure and from the Newport Inglewood fault itself. Observing the wavefield both in space and time clearly improves understanding of wave propagation complexities due to structural heterogeneity.

scholarly journals Effect of Mimic Vegetation with Different Stiffness on Regular Wave Propagation and Turbulence

Water ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 109 ◽  
Author(s):  
Chao Tan ◽  
Bensheng Huang ◽  
Da Liu ◽  
Jing Qiu ◽  
Hui Chen ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Elastic Modulus ◽  
Velocity Distribution ◽  
Turbulence Intensity ◽  
Secondary Wave ◽  
Flume Experiment ◽  
Regular Wave ◽  
Wave Dissipation ◽  
Flume Experiments ◽  
Dissipation Coefficient

Flume experiments were performed to test four plant mimics with different stiffness to reveal the effect of plant stiffness on the wave dissipation and turbulence process. The mimics were built of silica gel rod groups, and their bending elastic modulus was measured as a proxy for stiffness. The regular wave velocity distribution, turbulence characteristics, and wave dissipation effect of different groups were studied in a flume experiment. Results show that, when a wave ran through the flexible rod groups, the velocity period changed gradually from unimodal to bimodal, and the secondary wave peak was more apparent in the more flexible mimics. The change in the turbulence intensity in the different rod groups showed that the higher the rod stiffness, the greater the turbulence intensity. With an increase in the bending elastic modulus of a rod group, the wave dissipation coefficient increased. The increase in the wave dissipation coefficient was not linearly correlated with the bending elastic modulus, but it was sensitive within a certain range of the elastic modulus.

Design of High Elastic Modulus Alloy Using First Principles Electronic Theory

1990 ◽  
Vol 186 ◽  
Author(s):  
K. Masuda-Jindo ◽  
K. Terakura
Keyword(s):  
Elastic Modulus ◽  
Elastic Properties ◽  
First Principles ◽  
Theoretical Calculations ◽  
Spherical Wave ◽  
Wave Method ◽  
Lattice Constants ◽  
Simple Curves ◽  
Solute Atoms ◽  
Fcc Alloys

AbstractThe first principles ASW (augmented spherical wave) method is used to predict the elastic properties of Al-base and Ni-base fcc alloys. It is shown that the elastic modulus increase or decrease of the fcc alloys is closely correlated with the change in the lattice constants and that the results for various solute atoms can be summarized in the simple curves, depending on the species of the solute atoms. We demonstrate that the theoretical calculations for the binary alloys can be used for the design of the (multi-component) fcc alloys with desired elastic properties and lattice constants.

Spherical wave propagation in a viscoplastic medium ? The case of unloading

1974 ◽  
Vol 20 (3-4) ◽  
pp. 153-166 ◽  
Author(s):  
M. P. Zabinski ◽  
A. Phillips
Keyword(s):  
Wave Propagation ◽  
Spherical Wave ◽  
Viscoplastic Medium

scholarly journals A stable implementation measure of multi-transmitting formula in the numerical simulation of wave motion

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243979
Author(s):  
Jie Su ◽  
Zhenghua Zhou ◽  
Yuandong Li ◽  
Bing Hao ◽  
Qing Dong ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Numerical Solutions ◽  
Scattering Problem ◽  
Spherical Wave ◽  
Initial Boundary ◽  
Hyperbolic Partial Differential Equations ◽  
Initial Boundary Value Problems ◽  
Wave Source ◽  
Initial Boundary Value ◽  
Drift Instability

The Multi-Transmitting Formula (MTF) proposed by Liao et al. is a local artificial boundary condition widely used in numerical simulations of wave propagation in an infinite medium, while the drift instability is usually caused in its numerical implementation. In view of a physical interpretation of the Gustafsson, Kreiss and Sundström criterion on numerical solutions of initial-boundary value problems in the hyperbolic partial differential equations, the mechanism of the drift instability of MTF was discussed, and a simple measure for eliminating the drift instability was proposed by introducing a modified operator into the MTF. Based on the theory of spherical wave propagation and damping effect of medium, the physical implication on modified operator was interpreted. And the effect of the modified operator on the reflection coefficient of MTF was discussed. Finally, the validity of the proposed stable implementation measure was verified by numerical tests of wave source problem and scattering problem.

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