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Accurate numerical simulation of Eddy-Current Testing (ECT) experiments usually requires large computational efforts. So, a natural idea is to build a cheap approximation of the expensive-to-run simulator. This paper presents an approximation method based on functional kriging. Kriging is widely used in other domains, but is still unused in the ECT community. Its main idea is to build a random process model of the simulator. The extension of kriging to the case of functional output data (which is the typical case in ECT) is a recent development of mathematics. The paper introduces functional kriging and illustrates its performance via numerical examples using an ECT simulator based on a surface integral method. A comparison with other classical data interpolation methods is also carried out. [ABSTRACT FROM AUTHOR]

Practical quantities have been introduced by the authors to characterize the interaction among multiple defects located in a specimen under eddy-current testing (ECT). If these quantities indicate that the interaction between the pairs of defects is negligible, the signal of an ECT probe for multiple defects can be calculated as the superposition of those signals, which are obtained for each defect as if it would be a single one. Conversely, if the criteria holds, the measured ECT signal can be decomposed into signals associated with the individual defects, which essentially simplifies the solution of the inverse problem of defect reconstruction. As an application of the criteria, the design of a novel barcoding system is presented, which is developed for marking metallic parts by laser treating, and where the applicability of linear signal processing methods for the reading out of the barcode is a requirement. [ABSTRACT FROM AUTHOR]

Global approximating function sets applicable to the solution of the integral equation used to calculate an eddy current testing probe signal are proposed. Rectangularly-shaped cracks normal to the surface of plate specimens are considered. The approximating functions are orthogonal harmonic functions satisfying the boundary conditions at the edges of the crack. The calculations using the proposed approximating functions are fast, numerically stable and provide a robust alternative to other methods used in the literature. A number of numerical examples are shown for illustration and discussed. [ABSTRACT FROM AUTHOR]

Eddy current testing (ECT) probe signal due to cracks can be predicted by separating the calculation steps to the evaluation of the incident field and the reaction of the crack. Finite element (FEM) and boundary integral (ElM) methods can be, for example, advantageously applied for the calculation of the incident and reaction fields, respectively. The computational environment presented in this paper allows the blending of the different calculation methods for the purpose of ECT probe signal calculation. As a result, a fast and versatile tool is obtained to calculate the signal of complicated ECT probes due to cracks. The developed approach is validated through comparisons with experimental data. [ABSTRACT FROM AUTHOR]

The reconstruction problem of porous silicon (PS) structures is investigated by means of a specific optimized inversion database. The database is supported by a generic n-dimensional adaptive anisotropic simplex mesh. The proposed mesh database carries additional information on the inverse problem: the number of database nodes indicates the relevance of the model used for the reconstruction, while the mesh structure reflects the capabilities of the inversion as well as the role of the chosen model parameters. Based on this information one is able to propose an optimal model for the given inverse problem. [ABSTRACT FROM AUTHOR]

Focuses on a study which calculated the time-dependent response of the interaction of a stratified plate specimen of linear conductor with a planar flaw and an eddy-current induction coil fed by a current pulse. Discussion on pulsed eddy-current testing methods; Calculation of the time-harmonic electromagnetic field; Computation of the time-dependent field; Examples of application.