scholarly journals Nondestructive Approach for Complex-Shaped Cracks in Concrete Structures by Electromagnetic Waves with FDTD Technique

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Ummu S. Sener ◽  
Sebahattin Eker
Keyword(s):  
Numerical Simulation ◽  
Electromagnetic Waves ◽  
Integral Domain ◽  
Fdtd Method ◽  
Dynamic Geometry ◽  
Concrete Surface ◽  
Transverse Magnetic ◽  
Step Function ◽  
Internal Crack ◽  
Surface Cracks

Concrete cracks have no specific shape and do not show linearity. Since the natural occurrences of concrete cracks make simulation identification difficult, rectangular step function and a dynamic geometry are used to define a concrete surface crack in the natural process. A novel interior crack expression is obtained by accepting the area between two curves as a crack filled by air in concrete and modeling this area like a Riemann integral domain. Taking the partition of this integral domain, the most realistic definition of the crack is made. Electromagnetic (EM) waves are utilized for numerical simulation after identifying the defects, cracks, rebars, and geometry of concrete. Three different simulation setups with complex geometries with two different surface cracks and one internal crack are simulated using a finite-difference time-domain (FDTD) method with Gaussian pulse wave excitation. Simulations are obtained using both transverse electric (TEz) waves and transverse magnetic (TMz) waves and the results are compared with each other. Air-dried concrete specimens are molded following simulation setups with surface cracks and measurements are made nondestructively with a Vivaldi antenna array in the frequency range of 0.4–4.0 GHz. The reflection and transmission coefficients are validated by comparing the data obtained using the measurement with the results obtained from numerical simulation.

Propagation Analysis of Electromagnetic Waves in 700 MHz Band at Intersection for Inter-Vehicle Communications Using the FDTD Method

2011 ◽  
Vol E94-C (1) ◽  
pp. 18-23 ◽  
Author(s):  
Kenji TAGUCHI ◽  
Tatsuya KASHIWA ◽  
Kohzoh OHSHIMA ◽  
Takeshi KAWAMURA
Keyword(s):  
Electromagnetic Waves ◽  
Fdtd Method ◽  
Propagation Analysis

Electromagnetic field generated by an off‐axis source in a cylindrically layered medium with an arbitrary number of horizontal discontinuities

Geophysics ◽  
1993 ◽  
Vol 58 (5) ◽  
pp. 616-625 ◽  
Author(s):  
Qing‐Huo Liu
Keyword(s):  
Arbitrary Number ◽  
Electromagnetic Waves ◽  
Layered Medium ◽  
Azimuthal Angle ◽  
Well Logging ◽  
Transverse Magnetic ◽  
Numerical Results ◽  
Optical Fiber Communications ◽  
Eccentricity Effect ◽  
Large Eccentricity

We investigate the propagation of electromagnetic waves in a cylindrically layered medium with an arbitrary number of horizontal discontinuities. The dielectric constant, conductivity, and magnetic permeability of the medium are functions of ρ and z only (i.e., independent of the azimuthal angle ϕ), but the field generated by an off‐axis source in this medium is in general a function of ρ, ϕ, and z. This two and a half‐dimensional (2.5-D) problem is often encountered in electromagnetic well logging, as well as in other areas such as optical fiber communications and integrated optics. We show that a coupling exists between the transverse electric (TE) and transverse magnetic (TM) components of the field even in the absence of the horizontal discontinuities, which makes it difficult to solve for the field. We apply an efficient numerical mode‐matching (NMM) algorithm to tackle this 2.5-D problem. This algorithm uses the local reflection and transmission operators developed in the recent work on the diffraction of nonaxisymmetric waves in a cylindrically layered medium with a single horizontal discontinuity. For several special geometries, we compare the numerical results from this NMM algorithm with analytical solutions as well as the earlier numerical results for axisymmetric cases, and found excellent agreement between them. As an application to the geophysical subsurface sensing, we solve several practical problems, and find that a large eccentricity effect can occur in realistic electromagnetic well logging. Moreover, this large eccentricity effect is strongly coupled with thin‐bed effect. Conventional log interpretation methods cannot adequately account for these effects. With the NMM algorithm developed here, all these different effects can be accounted for simultaneously and accurately.

Numerical simulation for coupled nonlinear Schrödinger–Korteweg–de Vries and Maccari systems of equations

2021 ◽  
pp. 2150339
Author(s):  
Lanre Akinyemi ◽  
Pundikala Veeresha ◽  
Samuel Oluwatosin Ajibola
Keyword(s):  
Numerical Simulation ◽  
Plasma Physics ◽  
Acoustic Waves ◽  
Electromagnetic Waves ◽  
Nonlinear Partial Differential Equations ◽  
Transform Method ◽  
Langmuir Waves ◽  
Suggested Approach ◽  
Nonlinear Schrödinger ◽  
De Vries

The primary goal of this paper is to seek solutions to the coupled nonlinear partial differential equations (CNPDEs) by the use of q-homotopy analysis transform method (q-HATM). The CNPDEs considered are the coupled nonlinear Schrödinger–Korteweg–de Vries (CNLS-KdV) and the coupled nonlinear Maccari (CNLM) systems. As a basis for explaining the interactive wave propagation of electromagnetic waves in plasma physics, Langmuir waves and dust-acoustic waves, the CNLS-KdV model has emerged as a model for defining various types of wave phenomena in mathematical physics, and so forth. The CNLM model is a nonlinear system that explains the dynamics of isolated waves, restricted in a small part of space, in several fields like nonlinear optics, hydrodynamic and plasma physics. We construct the solutions (bright soliton) of these models through q-HATM and present the numerical simulation in form of plots and tables. The solutions obtained by the suggested approach are provided in a refined converging series. The outcomes confirm that the proposed solutions procedure is highly methodological, accurate and easy to study CNPDEs.

scholarly journals Multi-GPU numerical simulation of electromagnetic waves

2014 ◽  
Vol 45 ◽  
pp. 199-208 ◽  
Author(s):  
Philippe Helluy ◽  
Thomas Strub
Keyword(s):  
Numerical Simulation ◽  
Electromagnetic Waves

Automated image processing technique for detecting and analysing concrete surface cracks

2013 ◽  
Vol 9 (6) ◽  
pp. 567-577 ◽  
Author(s):  
Bang Yeon Lee ◽  
Yun Yong Kim ◽  
Seong-Tae Yi ◽  
Jin-Keun Kim
Keyword(s):  
Image Processing ◽  
Concrete Surface ◽  
Processing Technique ◽  
Image Processing Technique ◽  
Surface Cracks ◽  
Automated Image Processing

Numerical simulation of vacuum arc movement between transverse magnetic field contacts

2021 ◽  
Vol 28 (12) ◽  
pp. 123513
Author(s):  
Shixin Xiu ◽  
Yuzi Jiang ◽  
Zixi Liu ◽  
Zhanpeng Liu ◽  
Jinwang Yang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Numerical Simulation ◽  
Transverse Magnetic Field ◽  
Transverse Magnetic ◽  
Vacuum Arc

scholarly journals Features of electromagnetic wave propagation in two- and three-layer cylindrical dielectric waveguides

2019 ◽  
Vol 30 ◽  
pp. 06006
Author(s):  
Alexander G. Shein ◽  
Tatiana S. Kharlanova
Keyword(s):  
Electromagnetic Waves ◽  
Dielectric Waveguide ◽  
Electromagnetic Wave Propagation ◽  
Azimuthal Angle ◽  
Transverse Magnetic ◽  
Cylindrical Shape ◽  
Dielectric Waveguides ◽  
Power Flux ◽  
Open Dielectric Waveguide ◽  
Layer Waveguide

Various characteristics of electromagnetic waves propagating in two- and three-layer open-dielectric waveguide structures of cylindrical shape are studied. Parameters of wave components in separate areas of the waveguide are considered. Electrodynamic characteristics and frequency dependencies for several values of layer dielectric permittivity obtained during the study are analyzed. The corresponding graphs of dependencies are presented. The dependencies of the power flux density of transverse magnetic (TM) waves in two- and three-layer waveguide structures in the absence of field dependence on azimuthal angle are considered.

Numerical Simulation of the FDTD Method in LabVIEW [Application Notes]

2007 ◽  
Vol 8 (6) ◽  
pp. 90-99 ◽  
Author(s):  
Gasmelseed Akram ◽  
Yunus Jasmy
Keyword(s):  
Numerical Simulation ◽  
Fdtd Method
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