Three-dimensional inversion of eddy current data for non-destructive evaluation of steam generator tubes

Monebhurrun, Vikass; Duchêne, Bernard; Lesselier, Dominique

doi:10.1088/0266-5611/14/3/019

Cited by 27 publications

(34 citation statements)

References 22 publications

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“…2.2 VIM approach for 3D scalar case as coarse model to predict the ECT signal from narrow cracks This approach is analogous to previous research conducted by Monebhurrun et al (1998a, b). These authors confirmed that accounting for only one component of electric fields, in our case the xx component of the dyadic Green function, leads to a good numerical approximation of electric fields.…”

Section: Compel 313supporting

confidence: 81%

Space mapping methodology for defect recognition in eddy current testing – type NDT

Putek

Crevecoeur

Slodička

et al. 2012

COMPEL - The International Journal for Computation and Mathematics in Electrical and Electronic Engineering

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Purpose -The purpose of this paper is to solve an inverse problem of structure recognition arising in eddy current testing (ECT) -type NDT. For this purpose, the space mapping (SM) technique with an extraction based on the Gauss-Newton algorithm with Tikhonov regularization is applied. Design/methodology/approach -The aim is to have a computationally fast recognition procedure of defects since the monitoring results in a large amount of data points that need to be analyzed by 3D eddy current model. According to the SM optimization, the finite element method (FEM) is used as a fine model, while the model based on an integral method such as the volume integral method (VIM) serves as a coarse model. This approach, being an example of a two-level optimization method, allows shifting the optimization load from a time consuming and accurate model to the less precise but faster coarse surrogate. Findings -The application of this method enables shortening of the evaluation time that is required to provide the proper parameter estimation of surface defects. Research limitations/implications -In this work only the specific kinds of surface defects were considered. Therefore, the reconstruction of arbitrary shapes of defects when using real measurement data from ECT system can be treated in further research. Originality/value -The paper investigated the eddy current inverse problem. According to aggressive space mapping method, a suitable coarse model is needed. In this case, for the purpose of 3D defect reconstruction, the reduced VIM approach was applied. From a practical view point, the authors demonstrated that the two-level inversion procedures allow saving of up to 50 percent CPU time in comparison with the optimization by means of regularized Gauss-Newton algorithm in the same FE model.

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Section: Compel 313supporting

confidence: 81%

Space mapping methodology for defect recognition in eddy current testing – type NDT

Putek

Crevecoeur

Slodička

et al. 2012

COMPEL - The International Journal for Computation and Mathematics in Electrical and Electronic Engineering

View full text Add to dashboard Cite

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“…The configuration itself is taken from [13]. The tube wall is a highly conductive, non-magnetic material (Inconel 600: conductivity σ 0 = 0.98 × 10 6 Sm −1 ), and it is of internal and external radii of 9.83 and 11.1 mm, resp.…”

Section: Numerical Resultsmentioning

confidence: 99%

“…Primary eddy currents induced in the tube wall are modified by the defect. A receiving coil (Rx) sees it as a variation of voltage, or equivalently of mutual Tx-Rx impedance, which follows from the reciprocity theorem [13], [18]:…”

Section: A the Modelingmentioning

confidence: 99%

“…In section III the level-set method is discussed in detail, with most emphasis placed on the calculation of the gradient of the variation of impedance. Since, for comparison, one has also developed a binary-specialized method in harmony with the imaging of defects in a planar non-magnetic metal plate [12], with some know-how from [13], this method is summarized as well. Then, the practical implementation of the level-set evolution is discussed.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

3-D Eddy-Current Imaging of Metal Tubes by Gradient-Based, Controlled Evolution of Level Sets

et al. 2008

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Abstract-Eddy-current non-destructive testing is widely used to detect defects within a metal structure. It is also useful to characterize their location and shape provided that proper maps of variations of impedance which the defects induce are available. Imaging of void defects in the wall of a hollow, nonmagnetic metal tube, is performed herein by controlled evolution of level sets. Such data are variations of impedance collected by a circular probe array close to the inner surface of the tube when a coil source operated at one single frequency is set along its axis at some distance from the array, both receiver and coil source being moved simultaneously. The defect zone is represented in implicit fashion as a zero level set, amenable to topological changes via a nonlinear iterative method that minimizes a least-square cost functional made of the difference between the measured (computer simulated) and model data. The procedure involves the rigorous calculation of the gradient of the variations of impedance, in the case of a multi-static configuration (driver and receiver coils are different), a vector domain integral field formulation being used to that effect. Numerical examples, via a dedicated extension of the generalpurpose CIVA platform, exhibit pros and cons of the approach for inner, outer, and through-wall void defects, with further comparisons to results provided by an independently-developed binary-specialized method.

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“…The first group of models are numerical models such as a finite element model or integral equation models (Hoole et al 1991;Caorsi et al 1994;Monebhrrun et al 1998;Yan et al 1998;Balasubramanian et al 2001;Li et al 2001;Kim et al 2003;Arunachalam 2006;Connolly et al 2009), and although accurate, tend to be computationally expensive because the models must be solved during each iteration. Alternative forward models based on neural networks have also been proposed (Qing et al 1997;Zhang and Gupta 2000;Ramuhalli et al 2002Ramuhalli et al , 2003aJoshi 2006).…”

Section: Fault Diagnosticsmentioning

confidence: 99%

Prognostics and Health Management in Nuclear Power Plants: A Review of Technologies and Applications

Coble¹,

Ramuhalli²,

Bond³

et al. 2012

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Recent years have seen a resurgence of nuclear power worldwide, with interest in extending the operating life of the approximately 436 reactors currently in service (as of March, 2012), 61 new reactors being constructed, and as many as 162 under consideration. Renewed worldwide interest in nuclear power has been somewhat tempered by the March 2011 incident at Fukushima Dai-ichi in Japan. However, nuclear power is still considered a key element in meeting future worldwide sustainable energy, energy security, and emissions goals. Currently, three separate thrusts to safe and economical nuclear power development for energy security are being pursued in the United States: (i) longer term operation for the legacy fleet, from 40-60 and possibly 60-80 years; (ii) near-term new nuclear plants with a 60-year design life; and (iii) small modular reactors, which are expected to employ light water reactor technology at least in the medium term. Within these activities, attention is turning to enhanced methods for plant component and structural health management.The operating U.S. fleet includes 104 light water reactors. In addition, there are now (as of May 2012) four new nuclear power plants (AP-1000 plants) under construction in the United States, and two delayed plants are being completed by the Tennessee Valley Authority. There is also interest in the United States in small modular reactors (SMRs), which could be easier to match to existing grid infrastructure and which could replace aging coal fired plants. The current low price for natural gas presents a challenge to the economics of nuclear power, at least in the short term; however, some recent studies have demonstrated that nuclear generation will be competitive in the longer term (at least in some markets) when anticipated escalation in gas prices and the cost of building, operating, and maintaining gas-fired plants are considered over those same time periods.This report reviews the current state of the art of prognostics and health management (PHM) for nuclear power systems and related technology currently applied in field or under development in other technological application areas, as well as key research needs and technical gaps for increased use of PHM in nuclear power systems. The historical approach to monitoring and maintenance in nuclear power plants (NPPs), including the Maintenance Rule for active components and Aging Management Plans for passive components, are reviewed. An outline is given for the technical and economic challenges that make PHM attractive for both legacy plants through Light Water Reactor Sustainability (LWRS) and new plant designs. There is a general introduction to PHM systems for monitoring, fault detection and diagnostics, and prognostics in other, non-nuclear fields. The state of the art for health monitoring in nuclear power systems is reviewed. A discussion of related technologies that support the application of PHM systems in NPPs, including digital instrumentation and control systems, wired and wireless sensor techno...

show abstract

Three-dimensional inversion of eddy current data for non-destructive evaluation of steam generator tubes

Cited by 27 publications

References 22 publications

Space mapping methodology for defect recognition in eddy current testing – type NDT

Space mapping methodology for defect recognition in eddy current testing – type NDT

3-D Eddy-Current Imaging of Metal Tubes by Gradient-Based, Controlled Evolution of Level Sets

Prognostics and Health Management in Nuclear Power Plants: A Review of Technologies and Applications

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