scholarly journals Wave propagation in a viscoelastic medium with a high concentration of pores

1991 ◽  
Vol 89 (4B) ◽  
pp. 1859-1859
Author(s):  
Y. Ma ◽  
V. K. Varadan ◽  
V. V. Varadan ◽  
C. Audoly
Keyword(s):  
Wave Propagation ◽  
Viscoelastic Medium ◽  
High Concentration

scholarly journals Stress Wave Propagation through Rock Joints Filled with Viscoelastic Medium Considering Different Water Contents

2020 ◽  
Vol 10 (14) ◽  
pp. 4797 ◽  
Author(s):  
Xiaolin Huang ◽  
Shengwen Qi ◽  
Bowen Zheng ◽  
Youshan Liu ◽  
Lei Xue ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Water Content ◽  
Seismic Response ◽  
Transmission Coefficient ◽  
Stress Wave ◽  
Viscoelastic Medium ◽  
Rock Joints ◽  
Stress Wave Propagation ◽  
Multiple Reflections ◽  
Joint Spacing

A rock mass often contains joints filled with a viscoelastic medium of which seismic response is significant to geophysical exploration and seismic engineering design. Using the propagator matrix method, an analytical model was established to characterize the seismic response of viscoelastic filled joints. Stress wave propagation through a single joint highly depended on the water content and thickness of the filling as well as the frequency and incident angle of the incident wave. The increase in the water content enhanced the viscosity (depicted by quality factor) of the filled joint, which could promote equivalent joint stiffness and energy dissipation with double effects on stress wave propagation. There existed multiple reflections when the stress wave propagated through a set of filled joints. The dimensionless joint spacing was the main controlling factor in the seismic response of the multiple filled joints. As it increased, the transmission coefficient first increased, then it decreased instead, and at last it basically kept invariant. The effect of multiple reflections was weakened by increasing the water content, which further influenced the variation of the transmission coefficient. The water content of the joint filling should be paid more attention in practical applications.

Seismic modeling in viscoelastic media

Geophysics ◽  
1993 ◽  
Vol 58 (1) ◽  
pp. 110-120 ◽  
Author(s):  
José M. Carcione
Keyword(s):  
Wave Propagation ◽  
Viscoelastic Medium ◽  
Polynomial Interpolation ◽  
Superposition Principle ◽  
Forward Modeling ◽  
Memory Storage ◽  
Three Dimensions ◽  
Bright Spot ◽  
Viscoelastic Media ◽  
Standard Linear

Anelasticity is usually caused by a large number of physical mechanisms which can be modeled by different microstructural theories. A general way to take all these mechanisms into account is to use a phenomenologic model. Such a model which is consistent with the properties of anelastic media can be represented mechanically by a combination of springs and dash‐pots. A suitable system can be constructed by the parallel connection of several standard linear elements and is referred to as the general standard linear solid rheology. Two relaxation functions that describe the dilatational and shear dissipation mechanisms of the medium are needed. This model properly describes the short and long term behaviors of materials with memory and is the basis for describing viscoelastic wave propagation. This work presents two‐dimensional (2-D) and three‐dimensional (3-D) forward modeling in linear viscoelastic media. The theory implements Boltzmann’s superposition principle based on a spectrum of relaxation mechanisms in the time‐domain equation of motion by the introduction of the memory variables. The algorithm uses a polynomial interpolation of the evolution operator for time integration and the Fourier pseudospectral method for computation of the spatial derivatives. This scheme has spectral accuracy for band‐limited functions with no temporal or spatial dispersion, a very important fact in anelastic wave propagation. Examples are given of how to pose typical problems of viscoelastic forward modeling for geophysical problems in two and three dimensions. A model separating an elastic medium of a viscoelastic medium with similar elastic moduli but different attenuations shows that the interface generates appreciable reflected energy. A second example computes the response of a single interface in the presence of highly dissipative sandstone lenses, properly simulating the anelasticity of direct and converted P‐ and S‐waves. A common‐shot reflection survey over a gas cap reservoir indicates that attenuation significantly affects the bright spot response. 3-D viscoelastic modeling requires twice the memory storage of 3-D viscoacoustic modeling when one dissipation mechanism is used for each wave mode. Simulation in a 3-D homogeneous viscoelastic medium shows how the anelastic characteristics of the different modes can be controlled independently. The result of this simulation is compared to the analytical solution indicating sufficient accuracy for many applications.

scholarly journals Effect of viscoelastic medium on wave propagation along protein microtubules

AIP Advances ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 045108 ◽  
Author(s):  
Muhammad Safeer ◽  
M. Taj ◽  
Syed Solat Abbas
Keyword(s):  
Wave Propagation ◽  
Viscoelastic Medium
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