International Journal of Applied Electromagnetics and Mechanics - Volume 33, issue 3-4

Authors: Xie, Shejuan | Chen, Zhenmao | Takagi, Toshiyuki

Article Type: Research Article

Abstract: A fast forward scheme based on the Finite Element Method (FEM) and databases is proposed and developed for the rapid computation of Direct Current Potential Drop (DCPD) signals under condition of 3D FEM analysis for Nondestructive Testing (NDT) of Metallic Foam to reduce computer burden. Comparison of numerical results of the present method with those of full FEM code and experimental results of metallic foam indicates that the proposed novel fast forward scheme can predict DCPD …signals accurately and over 100 times faster. Show more

Keywords: Fast Forward Scheme, DCPD, Verification, NDT, Metallic Foam, Experiment

DOI: 10.3233/JAE-2010-1246

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1253-1260, 2010

Authors: Wang, Haitao | Luo, Qiufeng | Wang, Xin | Tian, Guiyun | Xing, Lidong | Wang, Ping | Li, Yong

Article Type: Research Article

Abstract: Remote-field eddy current (RFEC) inspection has shown its advantages over the other techniques in Electromagnetic non-destructive evaluation (ENDE) techniques in detection and characterization of deeper defects. In this paper, a new RFEC transducer has been designed for inspection of flat conductive plates, based on numerical simulations using finite element method. Through experimental study, it is concluded that the new transducer has the capability of detecting deep buried defects, and that the phase of RFEC signals have …linear relation with the depth of the defects. Show more

Keywords: Electromagnetic non-destructive evaluation, remote-field eddy current, flat conductive plates, finite element method

DOI: 10.3233/JAE-2010-1247

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1261-1266, 2010

Authors: Lekeaka-Takunju, Peter | Khan, Tariq | Bardel, Charles | Udpa, Satish | Udpa, Lalita | Kim, Jaejoon | Krzywosz, Kenji

Article Type: Research Article

Abstract: Fuel rods in nuclear power plants consist of uranium dioxide pellets enclosed in Zirconium alloy (Zircaloy) tubes. It is vitally important for the pellet surface to remain free from pits, cracks and chipping defects after it is loaded into the tubes to prevent local hot spots during reactor operation. The inspection of the fuel rod presents several challenges. In this paper, we investigate the feasibility of using X-ray tomography inspection to detect flaws on the surface …of pellets contained within the tubes using very limited number of projections. Show more

Keywords: Nuclear fuel pellets, X-ray tomography, limited projection, convex interpolation

DOI: 10.3233/JAE-2010-1248

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1267-1272, 2010

Authors: Li, Guohou | Huang, Pingjie | Chen, Peihua | Hou, Dibo | Zhang, Guangxin | Zhou, Zekui

Article Type: Research Article

Abstract: Eddy current testing (ECT) is a widely used nondestructive testing method in many such fields as the power system, railway, machinery, aircraft and nuclear industries. Because of the limitation of penetration depth of the conventional eddy currents testing coils and other affecting factors existing in the eddy current response, inverse problems to evaluate the deep defects from ECT signals of the conductive materials have been a challenging task. The objectives of this study are to introduce …methods based on the fuzzy Bayesian networks (BNs), and the giant magnetoresistance (GMR) sensors to estimate the deep defects from their ECT signals. The experimental validation carried out on the specimens with different known defects confirmed the suitability of the proposed approach for deep defects evaluation. Show more

Keywords: Eddy current testing, deep defects evaluation, fuzzy bayesian networks, radial base function neural network, giant magnetoresistance

DOI: 10.3233/JAE-2010-1249

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1273-1278, 2010

Authors: Lei, Naiguang | Udpa, Lalita | Udpa, Satish | Zeng, Zhiwei

Article Type: Research Article

Abstract: A novel design of eddy current probe based on rotating magnetic fields is presented for the inspection of steam generator tubes in nuclear power plants. A major advantage of the rotating field probe is that it offers the same functionality as that of a rotating probe coil without the need for mechanical rotation, which in turn translates into higher operating speed. The probe design is also sensitive to cracks of all orientations in the tube wall.

DOI: 10.3233/JAE-2010-1250

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1279-1285, 2010

Authors: Kai, Yuichiro | Tsuchida, Yuji | Enokizono, Masato

Article Type: Research Article

Abstract: This paper presents a frequency sweeping excitation and spectrogram(FSES) method to evaluate hardness and hardening depth of carbon steels by using electromagnetic methods. Magnetic properties of carbon steel samples under different hardening temperature condition are examined by using the FSES method. The results show that the magnetic properties of the hardened carbon steels differ depending on the hardening temperature. It can be said that the FSES method is useful to evaluate the hardening depth and the …hardness. Show more

Keywords: Hardening, carbon steel, eddy current coefficient, hysteresis coefficient, frequency sweeping excitation and spectrogram method

DOI: 10.3233/JAE-2010-1252

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1287-1294, 2010

Authors: Li, Luming | Zhong, Liqiang | Chen, Xing

Article Type: Research Article

Abstract: Residual stress concentration of welding joints is an essential factor to structure safety. It was found that the residual stress could generate a change of magnetic field in arc welding. Things became simple because of the methods based on measuring the distribution of the surface fields and analyzing the relation between the fields and the stress. However, we believe the fact that the magnetizing field caused by electrical current in arc welding has effects can not …be ignored. Also, the magnetic field of the Earth is sometimes considered as a critical point in the field's change. In this paper, experiments were carried out to study the role of arc current by comparing the methods of arc welding and laser welding. The magnetic field was measured upon the welding sites. By controlling the input energy, the residual stress was almost the same. The results obtained from these two welding methods varied. Magnetic fields testing from arc welding specimens were changed more sharply than the laser ones. This means that the magnetic change caused by electrical arc current is important to the surface field. Therefore, by analyzing the status of arc current, electro-magnetic methods can be used as non-destructive testing tool of the arc welding joints merely by testing the surface magnetic field without specific magnetization. Show more

Keywords: Non-destructive evaluation, residual stress, electrical arc, welding joint

DOI: 10.3233/JAE-2010-1253

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1295-1301, 2010

Authors: Oikawa, Ryota | Uchimoto, Tetsuya | Takagi, Toshiyuki | Urayama, Ryoichi | Nemoto, Yoshiyuki | Takaya, Shigeru | Keyakida, Satoshi

Article Type: Research Article

Abstract: This paper discusses the feasibility of non-linear eddy current method to evaluate material degradations of austenitic stainless steels associated with irradiation assisted stress corrosion cracking (IASCC). For the purpose, tensile tests at elevated temperatures are conducted using model alloys simulating radiation-induced segregation (RIS), and magnetization curves of the tensile test specimens are measured by vibrating sample magnetometer (VSM). Microstructure of magnetization of the tensile test specimens is observed by magnetic force microscopy …(MFM). Finally, non-linear eddy current method is carried out for the tensile test specimens. It is shown that the 3rd higher harmonic ratio of the pick-up signal is related to the targeted nominal strain. Show more

Keywords: Nondestructive evaluation, irradiation assisted stress corrosion cracking, non-linear eddy current method

DOI: 10.3233/JAE-2010-1254

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1303-1308, 2010

Authors: Lin, Junming | Li, Hanlin

Article Type: Research Article

Abstract: Integrated Non-Destructive Testing (NDT) is useful for industrial NDT applications. This paper introduces an integration technique of NDT data based on computer network. Integrated NDT technology increases compactness and performance of inspection instruments. The management and processing of NDT data becomes easier with the help of the integrated NDT method. At the same time, remote control of different on-line instruments is also achieved. Finally, a new type integrating testing equipments named EEC-2008net eddy …current and ultrasonic network testing system are briefly introduced. Show more

Keywords: Network, ET, UT, integrated system

DOI: 10.3233/JAE-2010-1255

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1309-1315, 2010

Authors: Urayama, Ryoichi | Uchimoto, Tetsuya | Takagi, Toshiyuki

Article Type: Research Article

Abstract: Eddy current testing (ECT) and ultrasonic testing (UT) have been widely used for the non-destructive testing of metal structures. ECT has a high capability of sizing surface breaking cracks and UT is suitable for sizing sub-surface breaking cracks in thick-wall structures. Based on this background, the authors have proposed a novel dual probe with simple structure combining an electromagnetic acoustic transducer (EMAT) and Eddy current probe. The performance of the probe was verified at room temperature. …However, the operating temperature of boiling-water nuclear reactors is 300 degrees C. In this paper, the above dual probe is applied to monitoring of piping wall thinning in a high temperature environment. For this purpose, the structure and components of the probe are discussed so that the present probe should withstand 300 degrees C. Finally, the basic performance of the probe at high temperatures is investigated through an experiment using an electric furnace. Show more

Keywords: High temperature monitoring, eddy current testing, electromagnetic acoustic transducer, dual probe, wall thinning

DOI: 10.3233/JAE-2010-1256

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1317-1327, 2010