Inverse Analysis for Inhomogeneous Dielectric Coefficient of Pavement Material Based on Genetic Algorithm

2013 ◽  
Vol 438-439 ◽  
pp. 430-435
Author(s):  
Xiang Hua Tao ◽  
Jing Qing Huang ◽  
Ying Chun Cai
Keyword(s):  
Genetic Algorithm ◽  
Background Noise ◽  
Inverse Analysis ◽  
Particle Surface ◽  
Pavement Materials ◽  
Reflected Wave ◽  
Inhomogeneous Dielectric ◽  
Dielectric Coefficient ◽  
Materials Used ◽  
Ground Penetrating

The key of ground penetrating radars application lies in the calculation of dielectric coefficient. The pavement materials are inhomogeneous medium in fact, the particle surface can induce the scatter and diffraction of electromagnetic wave. The inhomogeneous dielectricity can change the characteristics of reflected wave. It may even cause background noise of reflected signal, which will lead to mistakes in signal interpretation. Therefore it is necessary to analyze the inhomogeneous dielectric coefficients by GPR. This paper proposes the solutions of inverse analysis for inhomogeneous dielectric coefficients of pavement materials used GPR data. Two examples are given to assess the validity of genetic algorithms in inversion of pavement materials inhomogeneous dielectricity. The results show that genetic algorithm can converge into true solutions well. The backcalculated inhomogeneous dielectric coefficients can help to evaluate pavement properties further.

Cazacu and Barlat Criterion Identification Using the Cylindrical Cup Deep Drawing Test and the Coupled Artificial Neural Networks – Genetic Algorithm Method

2012 ◽  
Vol 504-506 ◽  
pp. 637-642 ◽  
Author(s):  
Hamdi Aguir ◽  
J.L. Alves ◽  
M.C. Oliveira ◽  
L.F. Menezes ◽  
Hedi BelHadjSalah
Keyword(s):  
Genetic Algorithm ◽  
Finite Element ◽  
Deep Drawing ◽  
Inverse Analysis ◽  
Computational Time ◽  
Ann Model ◽  
Drawing Test ◽  
Artificial Neural ◽  
Deep Drawing Test ◽  
Cylindrical Cup

This paper deals with the identification of the anisotropic parameters using an inverse strategy. In the classical inverse methods, the inverse analysis is generally coupled with a finite element code, which leads to a long computational time. In this work an inverse analysis strategy coupled with an artificial neural network (ANN) model is proposed. This method has the advantage of being faster than the classical one. To test and validate the proposed approach an experimental cylindrical cup deep drawing test is used in order to identify the orthotropic material behaviour. The ANN model is trained by finite element simulations of this experimental test. To reduce the gap between the experimental responses and the numerical ones, the proposed method is coupled with an optimization procedure based on the genetic algorithm (GA) to identify the Cazacu and Barlat’2001 material parameters of a standard mild steel DC06.

scholarly journals Inverse Analysis of Cracked Frame Structures by Genetic Algorithm.

1999 ◽  
Vol 65 (637) ◽  
pp. 1962-1968 ◽  
Author(s):  
Tadashi HORIBE ◽  
Naoki ASANO ◽  
Hiroyuki OKAMURA
Keyword(s):  
Genetic Algorithm ◽  
Inverse Analysis ◽  
Frame Structures

scholarly journals Lab Non Destructive Test to Analyze the Effect of Corrosion on Ground Penetrating Radar Scans

2019 ◽  
Vol 11 (23) ◽  
pp. 2814 ◽  
Author(s):  
Sossa ◽  
Pérez-Gracia ◽  
González-Drigo ◽  
Rasol
Keyword(s):  
Ground Penetrating Radar ◽  
Wave Amplitude ◽  
Metallic Surface ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Accurate Analysis ◽  
Reflected Wave ◽  
Dense Grid ◽  
Ground Penetrating ◽  
Non Destructive

Corrosion is a significant damage in many reinforced concrete structures, mainly in coastal areas. The oxidation of embedded iron or steel elements degrades rebar, producing a porous layer not adhered to the metallic surface. This process could completely destroy rebar. In addition, the concrete around the metallic targets is also damaged, and a dense grid of fissures appears around the oxidized elements. The evaluation of corrosion is difficult in early stages, because damage is usually hidden. Non-destructive testing measurements, based on non-destructive testing (NDT) electric and magnetic surveys, could detect damage as consequence of corrosion. The work presented in this paper is based in several laboratory tests, which are centered in defining the effect of different corrosion stage on ground penetrating radar (GPR) signals. The analysis focuses on the evaluation of the reflected wave amplitude and its behavior. The results indicated that an accurate analysis of amplitude decay and intensity could most likely reveal an approach to the state of degradation of the embedded metallic targets because GPR images exhibit characteristics that depend on the effects of the oxidized rebar and the damaged concrete. These characteristics could be detected and measured in some cases. One important feature is referred to as the reflected wave amplitude. In the case of corroded targets, this amplitude is lower than in the case of reflection on non-oxidized surfaces. Additionally, in some cases, a blurred image appears related to high corrosion. The results of the tests highlight the higher amplitude decay of the cases of specimens with corroded elements.

An Investigation of the Effect of Nanoparticles on the Effectiveness of a Heat Exchanger

2007 ◽  
Author(s):  
V. Upender Rao ◽  
V. Sajith ◽  
T. Hanas ◽  
C. B. Sobhan
Keyword(s):  
Thermal Conductivity ◽  
Heat Exchanger ◽  
Operating Temperature ◽  
Particle Surface ◽  
Weight Fraction ◽  
Copper Oxide Nanoparticles ◽  
Suspended Solid ◽  
Solid Particles ◽  
Particle Surface Area ◽  
Materials Used

Convective heat transfer can be improved by enhancing the thermal conductivity of the fluid. It has been established that fluids containing suspended solid particles of metallic origin in nanoscale dimensions, display enhanced thermal conductivity. Nanoparticle suspensions have superior qualities than suspensions of larger sized particles, such as more particle surface area, less possibilities of agglomeration and clogging and better stability. An experimental investigation on the effect of the inclusion of nanoparticles into the cooling fluid on the effectiveness of a heat exchanger is presented in this paper. An experimental double pipe heat exchanger with the hot fluid flowing through the inner tube was used in the study. Aluminum oxide and copper oxide nanoparticles with a size range of 20 to 30 nm suspended in water using ultrasonic agitation was used as the hot fluid, and water was used as the cold fluid passing through the annulus. The concentration of the suspended nanoparticles was varied to investigate its effect on the performance of the exchanger. The operating temperature is also used as a parameter in the study. Typically, an enhancement of 4.5 to 7 percent was observed in the effectiveness of the heat exchanger for 0.26% weight fraction of the nanoparticles in suspension, in an operating temperature range of 50–70°C. The effectiveness of the heat exchanger was found to increase with the concentration of nanoparticles for both materials used.

Cell planning scheme for WCDMA systems using genetic algorithm and measured background noise floor

2004 ◽  
Vol 151 (6) ◽  
pp. 595 ◽  
Author(s):  
H.-P. Lin ◽  
R.-T. Juang ◽  
D.-B. Lin ◽  
C.-Y. Ke ◽  
Y. Wang
Keyword(s):  
Genetic Algorithm ◽  
Background Noise ◽  
Noise Floor ◽  
Cell Planning ◽  
Planning Scheme

Bridge Slab Damage Detection by Signal Processing of UHF-Band Ground Penetrating Radar Data

2017 ◽  
Vol 12 (3) ◽  
pp. 415-421 ◽  
Author(s):  
Tsukasa Mizutani ◽  
◽  
Nagisa Nakamura ◽  
Takahiro Yamaguchi ◽  
Minoru Tarumi ◽  
...  
Keyword(s):  
Signal Processing ◽  
Developed Countries ◽  
Radar Data ◽  
Reflected Wave ◽  
The Developed Countries ◽  
Oil Source ◽  
Ground Penetrating ◽  
Processing Techniques ◽  
Signal Processing Techniques ◽  
Uhf Band

Maintenance costs for infrastructure, such as bridges, have been increasing particularly in the developed countries. Bridge slabs are important parts of bridges; however, the evaluation of their structural conditions requires significant manpower and time because dense hammering tests have to be conducted as part of the present inspection methods. To overcome this difficulty, a non-contact inspection technique using a radar is focused in this research. Radar techniques are typically utilized in the fields of mine-search, oil-source search, and geographical archeology. However, these searches are conducted by only visually checking reflected-wave images, and thus, the evaluation strongly depends on the abilities and expertise of the inspectors. To more effectively utilize these radar techniques for evaluating a bridge slab condition, analysis of the reflected wave signals should be made automatic, fast, and objective because the number of bridges to be inspected is large. In this research, to detect the damages on a slab, some signal processing techniques for measuring the reflected wave signal by a UHF-band fast scanning and non-contact radar are proposed, and their validity is shown by applying them to the signals obtained from full-scale bridge slab models in which certain ideal damages are embedded.

238 Corrosion Detection of Reinforcing Steel by Multistep Inverse Analysis using Genetic Algorithm and Net Element

2008 ◽  
Vol 2008.21 (0) ◽  
pp. 714-715
Author(s):  
Kazuhiro SUGA ◽  
Koichi MINAGAWA ◽  
Keisuke HAYABUSA ◽  
M. Ridha ◽  
Kenji AMAYA ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Inverse Analysis ◽  
Reinforcing Steel ◽  
Corrosion Detection

scholarly journals Testing Photovoltaic Pavers for Roadway Applications

2019 ◽  
Vol 4 (2) ◽  
pp. 86 ◽  
Author(s):  
Ronald A. Coutu, Jr. ◽  
David Newman ◽  
James Crovetti ◽  
Ashish Kumar Mishra ◽  
Mohiuddin Munna ◽  
...  
Keyword(s):  
Environmental Sustainability ◽  
Construction Materials ◽  
Extreme Temperature ◽  
Cost Savings ◽  
Motor Vehicles ◽  
Safety Standards ◽  
Pavement Materials ◽  
Roadway Construction ◽  
Materials Used ◽  
Dynamic Loading Conditions

<p><em>Concrete and asphalt are the primary materials used to construct roadways for motor vehicles, bike paths for pedestrians and bicyclists, and runways for aircraft. Solar Roadways®, Inc. (SR) in Sandpoint, ID, proposed using robust, Solar Road Panels (SRPs) as an alternative roadway material due to the potential for creating a modular, multi-functional infrastructure product with cost-savings, user-safety, power-generation, and a better alternative in terms of environmental sustainability when compared to contemporary pavement materials. Typical roadway construction materials, on average, need to be replaced every 10-15 years while also requiring regular annual maintenance to maintain proper safety standards. SR’s novel roadway material is intended to extend roadway replacement timelines, lower annual maintenance costs, and provide energy to the power grid. In this study, we tested the mechanical properties of the “SR3” model prototype SRP and evaluated its suitability as a replacement roadway material with the added benefit of generating electric power. Specifically, we tested this unique pavement material in submerged water environments, under extreme temperature conditions, and under dynamic loading conditions.</em></p>

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