A novel crack reconstruction method for steam generator tube ECT with noise sources outside

Huang, Haoyu; Takagi, Toshiyuki; Fukutomi, Hiroyuki
May 2000
AIP Conference Proceedings;2000, Vol. 509 Issue 1, p513
Academic Journal
In eddy current testing of steam generator tubes, the signals obtained are always noised by many factors because of the complex environment. Some of these noise factors are caused by the support plates, the expansion part of the tube and the tube sheets outside. Previous works show that the noises of support plates can be reduced by a multi-frequency method. However, the elimination of noises from the expansion part of the tube is proved impossible using the multi-frequency method only. A new signal processing method is introduced in this paper by applying a differential filter using the two dimensions scan data. Signal noise ratio (SNR) is increased significantly, even a small signal from outer defects can be recognized. Furthermore, a new method for the crack reconstruction from these noised signals has been developed with a fast signal prediction and the conjugate gradient algorithm considering the outside ferromagnetic structures such as support plates and tube sheets. The electromotive force signals used here for the crack reconstruction are laboratory data obtained by a newly developed four-sensor probe with mutual induction and differential outputs. Shapes of artificial cracks are reconstructed satisfactorily in short CPU time. © 2000 American Institute of Physics.


Related Articles

  • Inverse problems in eddy current testing using neural network. Yusa, N.; Cheng, W.; Miya, K. // AIP Conference Proceedings;2000, Vol. 509 Issue 1, p549 

    Reconstruction of crack in conductive material is one of the most important issues in the field of eddy current testing. Although many attempts to reconstruct cracks have been made, most of them deal with only artificial cracks machined with electro-discharge. However, in the case of natural...

  • Fast algorithms for crack simulation and identification in eddy current testing. Albanese, R.; Rubinacci, G.; Tamburrino, A.; Villone, F. // AIP Conference Proceedings;2000, Vol. 509 Issue 1, p505 

    Examines simulation and identification of cracks in eddy current testing for general purpose electromagnetic analysis. Imposition of the electric constitutive equation; Evaluation of the magnetic signal for given shape of the flaw; Determination of the modified eddy current pattern.

  • Eddy current monitoring of fatigue crack growth in Zr-2.5% Nb pressure tube. Krause, T. W.; Martin, A. E.; Sheppard, R. R.; Schankula, J. J. // AIP Conference Proceedings;2000, Vol. 509 Issue 1, p457 

    Zr-2.5% wt. Nb pressure tubes (PTs) form the core of the heat transport system in CANDU nuclear reactors. These 6 m long, 100 mm diameter tubes are operated at elevated temperatures (nominally 300 °C) and at pressures that produce hoop stresses that are 25% of the ultimate tensile strength of...

  • Inversion of open cracks using eddy-current probe impedance measurements. Bowler, J. R. // AIP Conference Proceedings;2000, Vol. 509 Issue 1, p529 

    Crack profiles have been estimated by the inversion of eddy-current probe impedance data. In the calculations, the direct problem is solved numerically to obtain predictions of impedance. A penalty function is constructed quantifying the overall difference between predictions and measurements....

  • Distribution of eddy current along an ideal surface crack. Liaw, J. W.; Chu, S. L.; Kuo, M. K.; Yeh, C. S. // AIP Conference Proceedings;2000, Vol. 509 Issue 1, p417 

    In this paper, a set of integral equations is derived systematically for the eddy current interacting with an ideal surface crack. An auxiliary surface integral equation is derived particularly for further determining the currents on both sides of the crack. These integral equations are solved...

  • Eddy current array probe for corrosion mapping on ageing aircraft. Leclerc, Re´mi; Samson, Rock // AIP Conference Proceedings;2000, Vol. 509 Issue 1, p489 

    The life of an airplane in the civil and military fleet is expanding by many years. The corrosion on aircraft is becoming a serious problem. The corrosion can also lead to the development of “multi-site damage” (MSD) and catastrophic failure. The need for a fast and reliable...

  • Neural network inversion of synthetic eddy current testing signals from flaws in steam generator tubes. Song, S. J.; Kim, C. H.; Shin, Y. K.; Lee, H. B.; Park, Y. W.; Yim, C. J. // AIP Conference Proceedings;2001, Vol. 557 Issue 1, p664 

    This paper reports our recent endeavor to develop automated, systematic inversion tools by the novel combination of neural networks and finite element modeling for eddy current flaw characterization in steam generator tubes. Specifically, this paper describes 1) development of the finite element...

  • Eddy Current Modeling of Coils in Boreholes. Theodoulidis, Theodoros P.; Bowler, John R. // AIP Conference Proceedings;2007, Vol. 894 Issue 1, p233 

    In both aircraft bolt-hole and steam generator tube inspections, eddy current probes are utilized to scan the inner surface of the cylindrical structure for defects. A combination of integral methods and analytical approaches provide an effective means of simulating such inspections thereby...

  • Eddy current imager based on bobbin-type hall sensor arrays for nondestructive evaluation in small-bore piping system. Jun, Jongwoo; Lee, Jinyi; Kim, Jungmin; Le, Minhhuy; Lee, Sehoon // AIP Conference Proceedings;Jan2013, Vol. 1511 Issue 1, p502 

    A bobbin coil with bobbin-type solid-state Hall sensor arrays was proposed for eddy current testing. A 32×32 matrix of InSb Hall sensors was set on a cylinder 15 mm in diameter and 25 mm long. The distorted alternating magnetic fields around inner diameter (ID) and outer-diameter stress...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics