TY - JOUR

T1 - Fast signal predictions of noised signals in eddy current testing

AU - Takagi, Toshiyuki

AU - Huang, Haoyu

AU - Fukutomi, Hiroyuki

PY - 1999

Y1 - 1999

N2 - This paper describes a new method for the simulations of signals noised by the presence of other materials except for test articles in eddy current testing (ECT). In the inspection of steam generator tubes in nuclear power plants, the sensor detects structures, for example support plates to fix the tubes, and deposits adhering to their outside, as well as tube defects. The signals from the structures are. thought to be noises when finding the defects. The method developed here is based on a set of governing equations constructed with magnetic vector potentials, introducing a precondition that a small part of the inverse matrix of the coefficient matrix in an algebraic equation from finite elements and the potentials for the unHawed conductor model are stored. Following the reciprocity theorem, an impedance change due to a flaw, as an eddy current signal, can be computed through integration in the flaw region, and unknowns corresponding to the flaw region only are considered. It results in much smaller degrees of freedom than typical finite element approaches require, and the method provides a fast forward simulator. The fast forward simulator is tested with experimental measurements of ECT benchmark problems with noise factors mentioned above, and is compared with a conventional approach from the point of view of computational costs.

AB - This paper describes a new method for the simulations of signals noised by the presence of other materials except for test articles in eddy current testing (ECT). In the inspection of steam generator tubes in nuclear power plants, the sensor detects structures, for example support plates to fix the tubes, and deposits adhering to their outside, as well as tube defects. The signals from the structures are. thought to be noises when finding the defects. The method developed here is based on a set of governing equations constructed with magnetic vector potentials, introducing a precondition that a small part of the inverse matrix of the coefficient matrix in an algebraic equation from finite elements and the potentials for the unHawed conductor model are stored. Following the reciprocity theorem, an impedance change due to a flaw, as an eddy current signal, can be computed through integration in the flaw region, and unknowns corresponding to the flaw region only are considered. It results in much smaller degrees of freedom than typical finite element approaches require, and the method provides a fast forward simulator. The fast forward simulator is tested with experimental measurements of ECT benchmark problems with noise factors mentioned above, and is compared with a conventional approach from the point of view of computational costs.

KW - Benchmark problems

KW - Deposits

KW - Eddy current testing

KW - Edge-based finite elements

KW - Magnetic vector potentials

KW - Reciprocity theorems

KW - Steam generator tubes

KW - Support plates

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U2 - 10.1299/kikaia.65.2024

DO - 10.1299/kikaia.65.2024

M3 - Article

AN - SCOPUS:71449105013

SN - 0387-5008

VL - 65

SP - 2024

EP - 2031

JO - Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A

JF - Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A

IS - 638

ER -