Static and Dynamic Backcalculation Analyses of an Inverted Pavement Structure

2013 ◽  
Vol 723 ◽  
pp. 196-203 ◽  
Author(s):  
James Maina ◽  
Wynand JvdM Steyn ◽  
Emile B. van Wyk ◽  
Frans le Roux
Keyword(s):  
South African ◽  
Maintenance Strategy ◽  
Falling Weight Deflectometer ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Back Calculation ◽  
The Difference ◽  
Falling Weight ◽  
Non Destructive ◽  
Crucial Part

A crucial part of any maintenance strategy is an intricate understanding of the material characteristics of the pavement, so that the current level of damage may be accurately assessed and an appropriate plan implemented. Advances in the precision to which these parameters can be determined, as well as improvements in how these results are interpreted under varying conditions of measurement and analysis, are essential in the effective execution of a maintenance strategy. Results from Falling Weight Deflectometer (FWD), which is a Non-Destructive Testing (NDT) device, can be used to predict elastic modulus of any layer by comparing measured deflection data to calculated values through an iterative process referred to as back-calculation. This paper presents a comparison between static and dynamic back-calculation procedures, specifically with regard to typical South African inverted pavements. The analysis indicates a dynamic analysis provides results of greater accuracy than a static analysis, although the effect of the difference requires further investigation.

Development of a Portable near Infrared Sugar-Measuring Instrument

2002 ◽  
Vol 10 (1) ◽  
pp. 77-83 ◽  
Author(s):  
Tsuyoshi Temma ◽  
Kenkoh Hanamatsu ◽  
Fujitoshi Shinoki
Keyword(s):  
Fruits And Vegetables ◽  
Near Infrared ◽  
Sugar Content ◽  
Processing Unit ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
General Chemical ◽  
The Difference ◽  
Brix Value ◽  
Non Destructive

Industries from agriculture to petrochemistry have found near infrared (NIR) spectroscopic analysis useful for quality control and quantitative analysis of materials and products. The general chemical, polymer chemistry, petrochemistry, agriculture, food and textile industries are currently using NIR spectroscopic methods for analysis. In this study, we developed a portable NIR instrument for the non-destructive testing of products in the field, which has resulted in an instrument for commercial sale and use. The instrument consists of a light source, a polychromator, a wave-guide (optical fibre bundle) and a data processing unit. We tested the performance of the portable NIR instrument in determining the sugar content of apples. The performance was also examined at full width at half maximum ( FWHM) of the spectrum. The difference in the absorption of quartz and plastic fibres in the NIR was also compared. The sugar content measurements were confirmed by a high correlation to the Brix value of the apples, and the calibration showed the accuracy of the instrument in practice. Application of this instrument to fruits and vegetables other than apples was explored.

Development and Application of Neutron Imaging Technique at China Advanced Research Reactor

2016 ◽  
Vol 850 ◽  
pp. 153-160 ◽  
Author(s):  
Lin Feng He ◽  
Song Bai Han ◽  
Guo Hai Wei ◽  
Mei Mei Wu ◽  
Yu Wang ◽  
...  
Keyword(s):  
Research Reactor ◽  
Neutron Imaging ◽  
Non Destructive Testing ◽  
Transmission Characteristics ◽  
Destructive Testing ◽  
Two Phase ◽  
Penetration Length ◽  
X Ray Imaging ◽  
The Difference ◽  
Non Destructive

Neutron imaging (NI) has unique feature compared with X-ray imaging for the difference of the transmission characteristics through matters. The sensitivity to light elements, especially hydrogen, and the large penetration length through metals give it special advantages. NI has become a particularly useful universal technique for scientific and applied studies in various research disciplines. This article reviews the recent development of neutron imaging at China Advanced Research Reactor (CARR), including the instrumentations for indirect and real-time imaging and their application for non-destructive testing of nuclear fuel rod, two-phase flow, fuel cell, rock and concrete, etc.

The Science Behind Eddy Current and Remote Field Testing: For Condenser and Heat Exchanger Tubing

2016 ◽  
Author(s):  
Christopher Van Name ◽  
Gary Fischer ◽  
James Kocher
Keyword(s):  
Eddy Current ◽  
Field Testing ◽  
Power Grids ◽  
Single Frequency ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Balance Of Plant ◽  
The Difference ◽  
Increasing Demand ◽  
Non Destructive

With the increasing demand on the world’s power grids, now more then ever it is important to keep power plant condensers, feedwater heaters and balance of plant heat exchangers running at peak efficiency. While it is well known that keeping these units clean is important for maximizing power output, so too is monitoring each unit’s tube integrity and taking corrective action to prevent tube failure. The best way to monitor a unit’s tube integrity, detect patterns of tube wear and damage, and determine the specific wear and damage to a particular tube is through Non-Destructive Testing. Depending on the tube material, the best Non-Destructive Testing method to employ would be either Eddy Current Testing, Remote Field Testing or other variations of these electromagnetic techniques. This paper will discuss the science behind Eddy Current and Remote Field Testing, how they differ and which one to select depending on the situation. It will look at the construction of the probes and how they work. It will explain the difference between use of a single frequency or multiple frequencies and the advantages of multi-frequency testing. The paper will also identify the necessary procedure for a successful Non-Destructive Test, including the types of tubes that can be tested and tube preparation.

scholarly journals Estudio experimental del comportamiento a compresión de hormigones autocompactantes reforzados con fibras de acero = Experimental study of performance self-compacting concrete reinforced with steel fibers

2015 ◽  
Vol 1 (2) ◽  
pp. 17
Author(s):  
J. L. Sánchez ◽  
A. Cobo ◽  
B. Díaz ◽  
I Mateos
Keyword(s):  
High Performance ◽  
Steel Fibers ◽  
Non Destructive Testing ◽  
Compression Tests ◽  
Self Compacting Concrete ◽  
Destructive Testing ◽  
Speed Of Ultrasound ◽  
The Difference ◽  
Non Destructive ◽  
Non Destructive Techniques

Resumen El hormigón autocompactante reforzado con fibras de acero presenta simultáneamente las ventajas de los hormigones autocompactantes y de los reforzados con fibras. Se consigue un material de altas prestaciones en cuanto a su colocación en obra, tenacidad y ductilidad. En este trabajo se ha estudiado el comportamiento mecánico de un hormigón autocompactante reforzado con fibras de acero. Se han realizado ensayos a compresión a distintas edades, así como ensayos no destructivos (medida de la velocidad de ultrasonidos e índice esclerométrico). Los resultados muestran la variación de la respuesta del hormigón con el tiempo, la diferencia existente con los hormigones tradicionales y la viabilidad del empleo de técnicas no destructivas para el control de este tipo de hormigones.AbstractSelf-compacting steel fibers reinforced concrete simultaneously has the advantages of self-compacting concrete and reinforced with fibers. A material of high performance in their laying on site, toughness and ductility is achieved. This paper has studied the mechanical behavior of a self-compacting concrete reinforced with steel fibers. Have been made compression tests, as well as non-destructive testing (measuring the speed of ultrasound and sclerometer test). The results show the variation of the response of concrete with time, the difference with the traditional concrete and the feasibility of using non-destructive techniques for controlling this type of concrete.

Codes Comparison and Analysis of Dissimilar Metal Welds: Ultrasonic Testing in Nuclear Power Plants

2010 ◽  
Author(s):  
Zhimin Zhong ◽  
Goufeng Zhang ◽  
Guanghua Yuan
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Pressure Vessels ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Dissimilar Metal ◽  
The Difference ◽  
Non Destructive ◽  
Performance Demonstration

Dissimilar Metal Welds have been widely used at safe-related pressure vessels and piping in Nuclear Power Plants. Some industry codes have been developed for nuclear power plants, such as ASME BPVC volume III & XI, Germany KTA 3201.3 and 3201.4 code and Russia code of light water nuclear power plants. The difference of those codes and some industry feed backs and some experiment results have been briefly introduced and discussed. Furthermore, the inspection qualification or performance demonstration, one of new requirements of some codes, especially for pre-service and inservice inspection of nuclear power plants, really promote continual improvements of DMWs UT both on detection rate and sizing accuracy. Additional, these works really benefit the revision of EJ/T 1039-1996, Non-destructive testing for mechanical components in nuclear island of nuclear power plants, as china building more and more nuclear power plants.

Non destructive testing of works of art by terahertz analysis

2013 ◽  
Vol 64 (2) ◽  
pp. 21001 ◽  
Author(s):  
Jean-Luc Bodnar ◽  
Jean-Jacques Metayer ◽  
Kamel Mouhoubi ◽  
Vincent Detalle
Keyword(s):  
Non Destructive Testing ◽  
Destructive Testing ◽  
Works Of Art ◽  
Non Destructive

Modeling of a sensitive element on a planar mushroom-shaped metamaterial for non-destructive testing and searching for inhomogeneities in technological media

2020 ◽  
pp. 54-59
Author(s):  
A. A. Yelizarov ◽  
A. A. Skuridin ◽  
E. A. Zakirova
Keyword(s):  
Sensitive Element ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Resonant Frequency Shift ◽  
Maltese Cross ◽  
Informative Parameters ◽  
Non Destructive ◽  
Cross Type ◽  
Electrodynamic Structure ◽  
Electrophysical Parameters

A computer model and the results of a numerical experiment for a sensitive element on a planar mushroom-shaped metamaterial with cells of the “Maltese cross” type are presented. The proposed electrodynamic structure is shown to be applicable for nondestructive testing of geometric and electrophysical parameters of technological media, as well as searching for inhomogeneities in them. Resonant frequency shift and change of the attenuation coefficient value of the structure serve as informative parameters.

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