Electroelastic State of a Piezoelectric Half-Space with Holes and Cracks Under an Electric Field

2021 ◽  
Author(s):  
K. G. Khoroshev ◽  
Yu. A. Glushchenko
Keyword(s):  
Electric Field ◽  
Half Space

A study of electric field components in shallow water and water half-space models in seabed logging

2016 ◽  
Author(s):  
Amir Rostami ◽  
Hassan Soleimani ◽  
Noorhana Yahya ◽  
Tadiwa Elisha Nyamasvisva ◽  
Muhammad Rauf
Keyword(s):  
Electric Field ◽  
Shallow Water ◽  
Half Space

Degenerate plasma in a half-space under an external electric field

2006 ◽  
Vol 147 (3) ◽  
pp. 854-867 ◽  
Author(s):  
A. V. Latyshev ◽  
A. A. Yushkanov
Keyword(s):  
Electric Field ◽  
External Electric Field ◽  
Half Space ◽  
Degenerate Plasma

To: “The electromagnetic response of thin sheets buried in a uniformly conducting half‐space,” by R. Clark Robertson in January 1987 GEOPHYSICS, p. 108–117

Geophysics ◽  
1987 ◽  
Vol 52 (4) ◽  
pp. 583-583
Keyword(s):  
Electric Field ◽  
Half Space ◽  
Thin Sheet ◽  
Skin Depth ◽  
Modeling Technique ◽  
Electromagnetic Response ◽  
Thin Sheets ◽  
Incident Electric Field

On p. 112, the caption of Figure 4 should read “The (a) magnitude and (b) phase in radians of the x component of the horizontal electric field obtained for a square thin sheet of integrated conductivity 1 S, 8 skin depths on a side, buried at a depth of 0.1 skin depth when the incident electric field is x polarized. Each segment is 1 skin depth on a side.” On p. 114, the last sentence of the first paragraph in the Discussion should read “It is easy to see why the surface thin sheet is a popular modeling technique for magnetotelluric applications.”

3D finite-element forward modeling of electromagnetic data using vector and scalar potentials and unstructured grids

Geophysics ◽  
2014 ◽  
Vol 79 (4) ◽  
pp. E149-E165 ◽  
Author(s):  
Seyedmasoud Ansari ◽  
Colin G. Farquharson
Keyword(s):  
Finite Element ◽  
Electric Field ◽  
Half Space ◽  
Normal Component ◽  
Forward Modeling ◽  
Computational Domain ◽  
Disk Model ◽  
Weighted Residuals ◽  
Physical Scale ◽  
Scalar Potentials

We present a finite-element solution to the 3D electromagnetic forward-modeling problem in the frequency domain. The method is based on decomposing the electric field into vector and scalar potentials in the Helmholtz equation and in the equation of conservation of charge. Edge element and nodal element basis functions were used, respectively, for the vector and scalar potentials. This decomposition was performed with the intention of satisfying the continuity of the tangential component of the electric field and the normal component of the current density across the interelement boundaries, therefore finding an efficient solution to the problem. The computational domain was subdivided into unstructured tetrahedral elements. The system of equations was discretized using the Galerkin variant of the weighted residuals method, with the approximated vector and scalar potentials as the unknowns of a sparse linear system. A generalized minimum residual solver with an incomplete LU preconditioner was used to iteratively solve the system. The solution method was validated using five examples. In the first and second examples, the fields generated by small dipoles on the surface of a homogeneous half-space were compared against their corresponding analytic solutions. The third example provided a comparison with the results from an integral equation method for a long grounded wire source on a model with a conductive block buried in a less conductive half-space. The fourth example concerned verifying the method for a large conductivity contrast where a magnetic dipole transmitter-receiver pair moves over a graphite cube immersed in brine. Solutions from the numerical approach were in good agreement with the data from physical scale modeling of this scenario. The last example verified the solution for a resistive disk model buried in marine conductive sediments. For all examples, convergence of the solution that used potentials were significantly quicker than that using the electric field.

scholarly journals P-FFT Accelerated EFIE with a Novel Diagonal Perturbed ILUT Preconditioner for Electromagnetic Scattering by Conducting Objects in Half Space

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Lan-Wei Guo ◽  
Yongpin Chen ◽  
Jun Hu ◽  
Joshua Le-Wei Li
Keyword(s):  
Integral Equation ◽  
Electric Field ◽  
Half Space ◽  
Electromagnetic Scattering ◽  
High Performance ◽  
Three Dimensional ◽  
Scattering Problems ◽  
Geometrical Structures ◽  
Incomplete Lu Factorization ◽  
Field Integral

A highly efficient and robust scheme is proposed for analyzing electromagnetic scattering from electrically large arbitrary shaped conductors in a half space. This scheme is based on the electric field integral equation (EFIE) with a half-space Green’s function. The precorrected fast Fourier transform (p-FFT) is first extended to a half space for general three-dimensional scattering problems. A novel enhanced dual threshold incomplete LU factorization (ILUT) is then constructed as an effective preconditioner to improve the convergence of the half-space EFIE. Inspired by the idea of the improved electric field integral operator (IEFIO), the geometrical-optics current/principle value term of the magnetic field integral equation is used as a physical perturbation to stabilize the traditional ILUT perconditioning matrix. The high accuracy of EFIE is maintained, yet good calculating efficiency comparable to the combined field integral equation (CFIE) can be achieved. Furthermore, this approach can be applied to arbitrary geometrical structures including open surfaces and requires no extra types of Sommerfeld integrals needed in the half-space CFIE. Numerical examples are presented to demonstrate the high performance of the proposed solver among several other approaches in typical half-space problems.

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