International Journal of Applied Electromagnetics and Mechanics - Volume 15, issue 1-4

Article Type: Editorial

Abstract: Preface to the Proceedings of the tenth International Symposium on Applied Electromagnetics and Mechanics ISEM-Tokyo

DOI: 10.3233/JAE-2002-525

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 1-2, 2002

Authors: Itoh, Hitoshi | Sugiura, Toshihiko | Maruyama, Shinichi | Yokota, Shuhei | Enoeda, Mikio

Article Type: Research Article

Abstract: Engineering use of jointed materials requires quantitative inspection of the joints, though it has not been established yet. Electromagnetic acoustic transducers (EMATs) can generate and detect ultrasonic waves in a conductive specimen by electromagnetic coupling without any contact with a specimen. This feature gives EMATs an advantage over conventional ultrasonic transducers: theoretical modeling and formulation based on elastodynamics and electromagnetics can be obtained. In this research, a process of joint inspection using …EMATs was analyzed numerically. Numerical results of the wave propagation explain effects of the joint interface and of a joint failure on the propagation of ultrasonic waves and on the receiver signals, in terms of reflection and diffraction of the waves. Predicted receiver signals agree well with experimental results, which verifies our numerical approach. These results show a possibility of quantitative joint inspection using EMATs. Show more

DOI: 10.3233/JAE-2002-433

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 3-8, 2002

Authors: Tanaka, Motoo | Tsuboi, Hajeme

Article Type: Research Article

Abstract: Several types of finite element methods have been developed and shown the validity and the effectiveness for eddy current testing (ECT) problem. However, it is difficult to analyze the finite element model including two or more objects whose positions relatively change, such as conductor plate and ECT probe. Furthermore, it takes a large amount of computer resources to compute an accurate finite element model for a natural crack, because of the complex shapes and the narrow …gap. In this paper, a superposition method to avoid the finite element mesh regeneration for the relative position change is presented, and the method is applied to the ECT probe with a ferrite core. Furthermore, the finite element model for the natural crack is shown and the model is applied to the ECT problem with the fatigue crack. Show more

DOI: 10.3233/JAE-2002-519

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 9-14, 2002

Authors: Kacprzak, Dariusz | Yamada, Sotoshi | Iwahara, Masayoshi

Article Type: Research Article

Abstract: This paper presents simulated amplitude and phase characteristics obtained during the inspection of printed circuit board by an eddy-current testing probe. The simulation is based on the ``two-components'' nature of the output signal. Amplitude and phase characteristics, obtained during the experimental inspection and simulation, are presented.

DOI: 10.3233/JAE-2002-425

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 15-19, 2002

Authors: Sikora, Ryszard | Komorowski, Mieczysław | Gratkowski, Stanisław | Enokizono, Masato | Chady, Tomasz

Article Type: Research Article

Abstract: The paper presents a simplified mathematical model of a magnetoresistive transducer, which is used for eddy current non-destructive testing of conducting materials.

DOI: 10.3233/JAE-2002-502

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 21-25, 2002

Authors: Hashimoto, Mitsuo | Kosaka, Daigo | Ooshima, Kenichi | Nagata, Yasutaka

Article Type: Research Article

Abstract: The eddy current testing is used for a testing of the steam generator tubes in pressurized water reactor nuclear power plants because of its high accuracy and high speed. It is important to judge shape of cracks from measured signals. We have developed a rotating type probe using an excitation coil that generates uniform eddy current distribution. Because the shape of excitation current source has no influence on detecting cracks, numerical analyses for this probe are …handled simply by devising boundary condition. Aid of numerical analyses has enhanced the evaluation of complicated cracks. Show more

DOI: 10.3233/JAE-2002-511

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 27-32, 2002

Authors: Chady, Tomasz | Enokizono, Masato | Sikora, Ryszard | Takeuchi, Kazuhiro | Kinoshita, Toshihiro

Article Type: Research Article

Abstract: The purpose of this paper is to present the results of observation of concrete damage using a newly developed eddy current sensor and a high performance multi-frequency system. Selected digital signal processing algorithms were applied in order to enhance the obtained signals. The experimental verification of the developed technique is done and the elected results are presented.

DOI: 10.3233/JAE-2002-503

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 33-37, 2002

Authors: Shekhar, H. | Polikar, R. | Ramuhalli, P. | Liu, X. | Das, M. | Udpa, L. | Udpa, S.S.

Article Type: Research Article

Abstract: An automated algorithm is presented for the analysis and classification of eddy current bobbin probe data obtained from nuclear power plant steam generator tubes (SGT). This algorithm attempts to find a balance between the two seemingly conflicting requirements of SGT eddy current data analysis, namely, detecting and identifying as many of the actual defects as possible, whilst limiting the number of false alarms to a minimum. Initial results presented in this paper look very promising.

DOI: 10.3233/JAE-2002-428

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 39-46, 2002

Authors: Kataoka, Yasuhiro | Murayama, Shuhei | Wakiwaka, Hiroyuki | Shinoura, Osamu

Article Type: Research Article

Abstract: We have developed a GMR line sensor which can arrange many GMR elements in a line on a polyimide film. This GMR line sensor detects the magnetic field distribution in a plane by only a single scan. We use the multilayer GMR element. This element can detect a magnetic field impress from directions of an element length and an element width. And the GMR line sensor has omnidirectional magnetic sensitivity. We applied this sensor to a …nondestructive magnetic leakage flux testing. The output of this sensor does not depend on the direction of leakage flux, therefore, this sensor can detect any direction of defect. Using the GMR line sensor, the shape of the defect will be identified by a single scan. Show more

DOI: 10.3233/JAE-2002-427

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 47-52, 2002

Authors: Sebestyén, I. | Pávó, J.

Article Type: Research Article

Abstract: Detection of internal flaws in conducting materials with considerable thickness is difficult using eddy current tests. This paper presents an alternative method, which uses dc magnetic field excited by the current impressed across the conducting material. In this case the internal flaws give rise perturbations of current flow and consequently the magnetic field is also changed. Perturbations in the magnetic field can be detected by dc (direct current) sensors such as magnetoresistive or Fluxset sensors. In …this work numerically performed experiments are presented to recover flaws at the interfaces of metal parts jointed at high temperature by high intensity pressure. Show more

DOI: 10.3233/JAE-2002-430

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 53-60, 2002