scholarly journals Signal Propagation in Soil Medium: A Two Dimensional Finite Element Procedure

2021 ◽  
Author(s):  
Frank Kataka Banaseka ◽  
Kofi Sarpong Adu-Manu ◽  
Godfred Yaw Koi-Akrofi ◽  
Selasie Aformaley Brown
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Scattered Field ◽  
Radar Cross Section ◽  
Transverse Magnetic ◽  
Arbitrary Cross Section ◽  
Observation Angle ◽  
Two Dimensional ◽  
Total Field ◽  
Dimensional Finite Element

A two-Dimensional Finite Element Method of electromagnetic (EM) wave propagation through the soil is presented in this chapter. The chapter employs a boundary value problem (BVP) to solve the Helmholtz time-harmonic electromagnetic model. An infinitely large dielectric object of an arbitrary cross-section is considered for scattering from a dielectric medium and illuminated by an incident wave. Since the domain extends to infinity, an artificial boundary, a perfectly matched layer (PML) is used to truncate the computational domain. The incident field, the scattered field, and the total field in terms of the z-component are expressed for the transverse magnetic (TM) and transverse electric (TE) modes. The radar cross-section (RCS), as a function of several other parameters, such as operating frequency, polarization, illumination angle, observation angle, geometry, and material properties of the medium, is computed to describe how a scatterer reflects an electromagnetic wave in a given direction. Simulation results obtained from MATLAB for the scattered field, the total field, and the radar cross-section are presented for three soil types – sand, loam, and clay.

Application of coordinate transformation to two-dimensional scattering and diffraction problems

1969 ◽  
Vol 47 (7) ◽  
pp. 795-804 ◽  
Author(s):  
L. Shafai
Keyword(s):  
Electromagnetic Field ◽  
Differential Equations ◽  
Cross Section ◽  
Coordinate Transformation ◽  
Scattered Field ◽  
Arbitrary Cross Section ◽  
Surface Currents ◽  
Two Dimensional ◽  
Dimensional Problem ◽  
First Order

The two-dimensional problem of determining the electromagnetic field scattered by a cylinder of arbitrary cross section is reduced to the solution of first-order, coupled differential equations. The procedure for finding the surface currents, scattered field, and the scattering cross section for a perfectly-conducting cylinder is given in detail. A brief study of the scattering by a polygonal cylinder and n identical strips equally spaced azimuthally around the z axis is used to examine the behavior of the differential equations.

Safety Analysis of Cross Section of Sea Embankment and Viaduct

2013 ◽  
Vol 838-841 ◽  
pp. 1719-1725
Author(s):  
Guang Chao Pei ◽  
Xiao Min Zhang ◽  
Jin Yang Li ◽  
Dong Feng Li
Keyword(s):  
Finite Element ◽  
Static Analysis ◽  
Cross Section ◽  
Pile Foundation ◽  
Great Influence ◽  
Two Dimensional ◽  
Construction Sequence ◽  
Construction Period ◽  
Soft Foundation ◽  
Dimensional Finite Element

The construction sequence of cross section has a great influence on the construction security when the sea embankment is built across the viaduct and the construction period is close. In this paper, the two-dimensional finite element static analysis of consolidation is employed, and analyzes the effect of construction on the deformation and stress of sea embankment, bridge pier and the pile foundation. At the same time, the interaction principles of soft foundation and bridge are revealed. Put forward the suggested solution of sea embankment and viaduct construction sequence which can provide a reference for the coastal traffic and sea embankment construction.

Exact analysis of the bending of wide beams by a modified elastica approach

2011 ◽  
Vol 225 (11) ◽  
pp. 2759-2764 ◽  
Author(s):  
L F Campanile ◽  
R Jähne ◽  
A Hasse
Keyword(s):  
Finite Element ◽  
Substantial Reduction ◽  
Short Review ◽  
Computational Effort ◽  
Two Dimensional ◽  
Finite Element Calculations ◽  
Dimensional Finite Element ◽  
Wide Beams ◽  
Insight Into ◽  
Selection Of

Classical beam models do not account for partial restraint of anticlastic bending and are therefore inherently inaccurate. This article proposes a modification of the exact Bernoulli–Euler equation which allows for an exact prediction of the beam's deflection without the need of two-dimensional finite element calculations. This approach offers a substantial reduction in the computational effort, especially when coupled with a fast-solving schema like the circle-arc method. Besides the description of the new method and its validation, this article offers an insight into the somewhat disregarded topic of anticlastic bending by a short review of the published theories and a selection of representative numerical results.

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