Center For Nondestructive Evaluation Research Articles

NDT application for detection of corrosion under insulation in Vietnam

: In the oil and gas Industry, insulation materials can be used widely for piping system, tank and vessel in either low or high temperature applications. CUI can cause equipment degradation, fluid leak, which lead to explosion or environmental pollution and the cost will very expensive. Therefore, CUI need to be detected early to prevent damage. Through experiment, Center for Non-Destructive Evaluation (NDE) studied on establishing and appliying 4 NDT procedures for CUI examination on typical petroleum piping using in Vietnam. A discussion is presented below

An Introductory Note on Finite Element Problems Based on the Eddy Current Testing Approach

The paper addresses the first eddy current benchmark problem proposed by the World Federation of Nondestructive Evaluation Centers (WFNDEC). The problem simulates the eddy current response to the presence of an axisymmetric circumferential defect in an Inconel-600 tube. All simulations employ the axisymmetric code of the electromagnetic field simulator Finite Element Method Magnetics. For three different frequencies of excitation, it is explained how the displacement of the detecting coil inside the tube leads to a variation in the impedance of the eddy current coil. Variations of the resistive and inductive components of the impedance with distance from the defect region are used to build the impedance trajectory for each frequency of analysis.

Assessment of an X-ray analysis system for investigating of fibrous debris bed formation on PWR sump strainer modules

During the blow-down stage of a loss of coolant accident (LOCA), fibrous material and associated debris are transported from the location of the pipe break to the sump system as core coolant flows through containment. A series of strainer modules are installed to restrict large debris from entering the sump system, which supplies coolant to the Emergency Core Cooling System (ECCS). The accumulation of fibrous and debris material can result in the formation of semi-porous layers on the strainer module surfaces and possibly result in a reduction of coolant recirculation to the ECCS. The University of New Mexico (UNM) is investigating non-invasive techniques to better visualize the formation of fibrous debris beds on sump strainer modules; real-time visualization of debris bed formation would allow for better assessment of the filtration blockage of sump strainers. A series of exploratory tests were performed at the Center for Non-Destructive Evaluation (CNDE) at Iowa State University (ISU) to determine the viability of using an X-ray system to perform in situ measurements of debris bed formation and particulate filtration on small-scale representative sump pump strainer assemblies.

Using X-ray computed tomography to study paving materials

X-ray computed tomography, a non-destructive three-dimensional imaging tool, has been very helpful in medical diagnosis since the first commercial tomographs were constructed in 1973. In recent years it has gained increasing applications in civil engineering materials research. Several investigators have illustrated the use of computed tomography scans for the non-destructive evaluation of soils and have shown promising applications in characterisation, modelling and computational simulation to optimise asphalt concrete mix design, predict performance and conduct investigative forensic studies. This paper provides a detailed review of X-ray computed tomography applications in characterising asphalt concrete and also describes preliminary studies conducted at the Center for Nondestructive Evaluation (CNDE) at Iowa State University for characterising asphalt and concrete materials using X-ray microcomputed tomography or micro-computed tomography. Researchers are currently using the advanced imaging facilities available at the CNDE to develop a deeper understanding of the pavement internal structure, to develop and optimise the various parameters that describe the internal structure and to relate them to the performance of pavements in a scientific way. This will provide the foundations for building more durable and long-lasting transportation infrastructure systems.

Numerical simulation of a magnetic flux leakage benchmark problem

Three typical non-destructive benchmark problems on MFL testing modelling were proposed by the World Federation of Nondestructive Evaluation Centers to compare the numerical techniques used by different Federation Members, and validate them against experimental measurements. Within a framework of regional cooperation, the ENDE Group at Buenos Aires collaborated with GRUCAD at Florianopolis to apply to NDT the latter 's software for calculation of electromagnetic devices. This paper presents results from the first stage of this cooperation. Results obtained with a 2D-version of EFCAD with a regular mesh generator are presented here. These results compare well with those from the 3D simulations presented by other groups who took part in the benchmark problem project.

Making the Grade

This article highlights methods that are under study to bring non-destructive evaluation into wider use. Non-destructive evaluation is the subject of a good deal of research, which may soon make it easier than ever to integrate testing into assembly lines, and so may take the technology to new corners of industry. Increased sensitivity, higher computing power, and better imaging are improving the quality of information and ease of use. R. Bruce Thompson, Director of the Center for Non-destructive Evaluation at Iowa State University, Ames, points out that advances in sensing technology have improved understanding of how energy behaves in the microstructure of a material. One of the developments at Iowa State is a set of modelling tools to help determine if an investigative technique will be adequate. The US Department of Energy has a goal of using of lightweight materials in automobiles as an energy-conservation measure. Overall, manufacturers are acknowledging the value of selected non-destructive evaluation techniques, and researchers are getting better at adapting non-destructive evaluation techniques to the plant floor through portability, fine resolutions, and smart software.

Noncontact Acoustical Techniques for Nondestructive Characterization of Materials and Structures

The Johns Hopkins University Center for Nondestructive Evaluation (CNDE) is an interdisciplinary cooperative center between the university, government, and industrial organizations dedicated to the development of more accurate and innovative methods for the nondestructive evaluation of materials and to the education of talented students. This paper will describe several innovative noncontact nondestructive materials characterization methods developed in the CNDE. Lasers, optical interferometers, electro-magnetic transducers, and air(gas)-coupled systems are used for noncontact generation and detection of ultrasonic waves to inspect art paintings, metals, wood, and composites. Optical detection of acoustic emission signals permits detection of surface displacements caused by acoustic emission events without any modification of the detected waveforms or frequency spectra.

96/01566 PRA in the nuclear sector. Quantifying human error and human malice

During the blow-down stage of a loss of coolant accident (LOCA), fibrous material and associated debris are transported from the location of the pipe break to the sump system as core coolant flows through containment. A series of strainer modules are installed to restrict large debris from entering the sump system, which supplies coolant to the Emergency Core Cooling System (ECCS). The accumulation of fibrous and debris material can result in the formation of semi-porous layers on the strainer module surfaces and possibly result in a reduction of coolant recirculation to the ECCS. The University of New Mexico (UNM) is investigating non-invasive techniques to better visualize the formation of fibrous debris beds on sump strainer modules; real-time visualization of debris bed formation would allow for better assessment of the filtration blockage of sump strainers. A series of exploratory tests were performed at the Center for Non-Destructive Evaluation (CNDE) at Iowa State University (ISU) to determine the viability of using an X-ray system to perform in situ measurements of debris bed formation and particulate filtration on small-scale representative sump pump strainer assemblies.

96/01564 Options, experience and trends in spent fuel management

During the blow-down stage of a loss of coolant accident (LOCA), fibrous material and associated debris are transported from the location of the pipe break to the sump system as core coolant flows through containment. A series of strainer modules are installed to restrict large debris from entering the sump system, which supplies coolant to the Emergency Core Cooling System (ECCS). The accumulation of fibrous and debris material can result in the formation of semi-porous layers on the strainer module surfaces and possibly result in a reduction of coolant recirculation to the ECCS. The University of New Mexico (UNM) is investigating non-invasive techniques to better visualize the formation of fibrous debris beds on sump strainer modules; real-time visualization of debris bed formation would allow for better assessment of the filtration blockage of sump strainers. A series of exploratory tests were performed at the Center for Non-Destructive Evaluation (CNDE) at Iowa State University (ISU) to determine the viability of using an X-ray system to perform in situ measurements of debris bed formation and particulate filtration on small-scale representative sump pump strainer assemblies.

Up Close: Johns Hopkins Center for Nondestructive Evaluation

Nondestructive evaluation has historically been used almost exclusively for detecting macroscopic defects after materials have been made or put into service. However, the role of NDE is now changing to include in-process control in an effort to increase yields and performance of materials. This includes materials stability during transport, storage, and fabrication, as well as degradation behavior during in-service life. The NDE community has implied that applying NDE in these ways is crucial to solving the economic problems of U.S. manufacturing industries. So called “intelligent manufacturing” is impossible without integrating modern NDE techniques into the production of today's advanced materials.The Johns Hopkins University Center for Nondestructive Evaluation (CNDE) was established in 1984 as an interdisciplinary center for research and instruction, drawing on the resources and talent of the School of Engineering, Applied Physics Laboratory, School of Medicine, and School of Arts and Sciences. Currently 31 faculty or senior staff work with the Center. The techniques being developed are aimed at reliable in-process control of materials and processes. Another important purpose is the education of talented students who will enter the NDE field; 150 students are associated with the Center, a third of whom are graduate students. The CNDE also provides both research collaborators and industrial sponsors with access to all NDE research and instruction at Johns Hopkins University. Twenty-six research institutions have formal cooperative research programs and 19 organizations are corporate sponsors (see Figure 1).

Nondestructive Evaluation for Materials Characterization

AbstractIn recent years classical nondestructive testing techniques for detecting macroscopic defects have been augmented by more sophisticated nondestructive evaluation methods for characterizing the microstructure and associated physical and chemical properties of materials. This paper will briefly describe several such nondestructive evaluation methods developed in the Center for Nondestructive Evaluation (CNDE) at The Johns Hopkins University.

Center for Nondestructive Evaluation

ABSTRACTThe Johns Hopkins University Center for Nondestructive Evaluation (CNDE) has recently been established as an interdisciplinary center for research and instruction which draws on the resources and talent of the School of Engineering, the Applied Physics Laboratory, and the School of Medicine. The nondestructive evaluation techniques developed and employed are especially useful to control and improve product quality in manufacturing processes and to assure the highest level of reliability for materials, parts, and products. The center is dedicated to research which will lead to more sophisticated and accurate methods for the nondestructive evaluation of materials and systems and to the education of talented students who will enter the NDE field. The CNDE is a cooperative venture between the University, Industrial Affiliates, and Government Agencies. The present paper will describe the CNDE and the current and planned educational program in materials education.