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

Authors: Huang, Haoyu | Kayata, Ryo | Perrin, Stephane | Yusa, Noritaka | Miya, Kenzo

Article Type: Research Article

Abstract: A novel electromagnetic nondestructive evaluation (NDE) method was proposed by authors recently. Electromagnetic (EM) sensors, by directly measuring the impeller of a rotating machine, offer a powerful way to detect not only defects on the impeller itself but the state of the condition of the rotation, through the measurement of the displacement of the shaft and the impeller. In this paper, a numerical simulation method using magnetic vector potential and edge based finite element was presented. …Simulation results of the EM signals showed good agreement with experimental results of a small water pump. A real canned pump with magnetic casing was considered and numerical results showed that the electromagnetic nondestructive evaluation method is possible to detect the impeller covered by magnetic casing in some instances. Show more

Keywords: Electromagnetic nondestructive evaluation method, magnetic vector potential, edge based finite element method, rotating machinery, electromagnetic signal

DOI: 10.3233/JAE-2010-1226

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1101-1107, 2010

Authors: Zhang, Dongli | Chen, Zhenmao | Xu, Minglong | Lu, Tian-Jian

Article Type: Research Article

Abstract: Lattice sandwich metallic plate (LSMP) is an important multifunctional material. The strength of LSMP may be significantly affected by defects in its welding joints. In this paper, Direct Current Potential Drop (DCPD) in addition with a sizing indicator is proposed as a quantitative NDE tool to evaluate the welding defects in LSMP. Simulation and experimental results show that the proposed strategy is efficient for the quantitative NDT of welding defects in LSMP.

Keywords: Quantitative NDE, lattice sandwich metallic plate, welding defect, DCPD, numerical simulation, experiment

DOI: 10.3233/JAE-2010-1227

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1109-1117, 2010

Authors: Kobayashi, Satoru | Kikuchi, Nobuhiro | Kikuchi, Hiroaki | Kamada, Yasuhiro | Echigoya, Junichi

Article Type: Research Article

Abstract: We have examined scaling rules in magnetic minor hysteresis loops for strain-induced ferromagnetic α'-martensite in 304 stainless steels. The scaling power law between the hysteresis loss and remanence is found to be independent of volume fraction and morphology of martensite. A coefficient of the power law changes depending on size, shape and distribution of martensite. The present method can be a possible technique for integrity assessment of austenitic stainless steels because of the sensitivity …and low measurement field. Show more

Keywords: Magnetic hysteresis, Stainless steel, Martensite, Non-destructive testing

DOI: 10.3233/JAE-2010-1228

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1119-1125, 2010

Authors: Lu, Chao | Men, Ping | Li, Lianxiu

Article Type: Research Article

Abstract: A lab-based laser-EMAT (Electromagnetic acoustic transducers) system has been developed to observe the ultrasonic surface wave propagation and interaction with surface breaking defects on the sample rail head surface. The frequency-wavenumber dispersion curves of the dominant surface wave modes were determined using 2D-FFT method based on the measurements of the out-of-plane displacement of the surface wave. A complete picture of the ultrasonic surface wave on the sample surface over time was reconstructed with exceptionally high …spatial and temporal resolution. Despite the curvature of the rail head, the ultrasonic surface guided wave propagating down the rail is found to have similar properties to Rayleigh waves by direct comparison to those observed on flat samples using the same technique. Show more

Keywords: EMAT, ultrasonc surface waves, 2D-FFT, rail

DOI: 10.3233/JAE-2010-1229

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1127-1133, 2010

Authors: Ohtaki, Keitaro | Uchimoto, Tetsuya | Takagi, Toshiyuki

Article Type: Research Article

Abstract: Mechanical properties of cast irons strongly depend on the graphite morphology and the matrix structure, thus both of them should be evaluated for their characterization. The former can be evaluated by ultrasonic testing (UT), and the latter can be evaluated by eddy current testing (ECT). Considering the background above, this study proposes a novel method for the material characterization of cast irons with an EMAT/EC dual probe. For this purpose, we conducted UT and ECT for …cast irons with different graphite morphology and matrix structures with the present probe. As a result, correlations between the nodularity of graphite and ultrasonic velocity, and between one the pearlite ratio and EC signals were obtained. These results imply that the EMAT/EC dual probe is effective for the material characterization of cast irons. Show more

Keywords: Dual probe, electromagnetic acoustic transducer, eddy current testing, cast irons, matrix structure, graphite form

DOI: 10.3233/JAE-2010-1230

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1135-1141, 2010

Authors: Ren, Jilin | Pan, Qianghua | Yang, Sheng | Chen, Chen | Tang, Jihong

Article Type: Research Article

Abstract: Influenced by the earth magnetic field, indirection of the domain organization and irreversible reorientation will be occurred in internal organization of the loaded ferromagnetic material. The effects of stress on the domains of silicon steel sheet and 0.20% C carbon steel, which had been loaded on the different load, the domains have been observed with the Bitter method. The results show that the silicon steel and 0.20% C carbon steel with the low load or no …load, there mainly exist 180 domains, dendritic domains, gladiate domains whose walls are smaller each other in a same crystalline grain, then, with the load enhancing, the domain walls' length and space changed and there exits mazy I domains and mazy II domains, and the number of the mazy domains increase. Show more

Keywords: Magnetic Memory Test, magnetic domain, Bitter method, mazy domain

DOI: 10.3233/JAE-2010-1231

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1143-1148, 2010

Authors: Janousek, Ladislav | Smetana, Milan | Capova, Klara

Article Type: Research Article

Abstract: The paper focuses on increasing information level of response signals in eddy-current non-destructive inspection. A new eddy-current detection system is proposed in the study for enhancing quantitative evaluation of an indicated defect. It is composed of three circular inductance coils positioned perpendicularly to each other. The system allows sensing all of the three spatial components of the perturbation electromagnetic field. Thus more complex information about an inspected defect is gained. Numerical simulations …are carried out and the results are evaluated to demonstrate capabilities of the new system in reducing the ambiguity of crack sizing using eddy-current non-destructive inspection. Show more

Keywords: Non-destructive inspection, eddy-currents, detection system, response signals, information level, crack sizing

DOI: 10.3233/JAE-2010-1232

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1149-1155, 2010

Authors: Zuo, Yongbin | Chen, Zhenmao | Mao, Ying | Zhang, Jing

Article Type: Research Article

Abstract: In this paper, the performance of two probes of split TR structure is evaluated by numerical analysis aiming at the enhancement of sizing capability of ECT for a deep crack. The structures of the two probes are respectively of reflection and transmission type consisting of a rectangular excitation unit and a pancake pickup coil. A modified way is proposed for the reflection type probe to improve the eddy current penetration. Numerical results reveal that the modified …reflection type probe and the transmission type probe are promising for the sizing of deep cracks. Show more

Keywords: Split TR probes, deep cracks, ECT, numerical simulation

DOI: 10.3233/JAE-2010-1233

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1157-1164, 2010

Authors: Mihalache, Ovidiu | Yamaguchi, Toshihiko | Ueda, Masashi | Miyahara, Shinya

Article Type: Research Article

Abstract: Three-dimensional numeric simulations, based on the finite element model, are conducted to simulate the In-Service Inspection of magnetic steam generator tubes of a Fast Breeder Reactor using remote field eddy current probes. The influence of sodium in the gap SP-tube and outer defect detectability is computed for a large SP model with multiple SG tubes using the 3D-RFECT code.

Keywords: Finite element, steam generator, fast-breeder reactor, remote field eddy currents

DOI: 10.3233/JAE-2010-1234

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1165-1171, 2010

Authors: Sun, Xiao-Yun | Liu, Dong-Hui | Sheng, Jian-Ni

Article Type: Research Article

Abstract: For tube detection, an effective denoise method based on Hilbert-Huang Transform (HHT) is presented. At first, by using an empirical mode decomposition algorithm, a sum of Intrinsic Mode Functions (IMF) are obtained; then, the IMF coefficients in useful signal dominative layer are proceeded using soft threshold method; at last, those IMF coefficients are reconstructed. Compared with the traditional wavelet Transform, the HHT method is better to remove measurement noise.

Keywords: Denoise method, Hilbert-Huang Transform, empirical mode decomposition

DOI: 10.3233/JAE-2010-1235

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1173-1177, 2010