International Journal of Applied Electromagnetics and Mechanics - Volume 45, issue 1-4

Authors: Chen, Junjie | Huang, Songling | Zhao, Wei | Wang, Shen

Article Type: Research Article

Abstract: This paper proposes an inversion procedure, based on radial wavelet basis function (RWBF) neural network, to reconstruct 3-D defect profiles from magnetic flux leakage (MFL) data. The architecture of the neural network, the adaptive training algorithm and the reconstruction process are presented. Defects reconstructed from both simulated and experimental MFL data, together with comparison with two other inversion methods, demonstrate the efficiency and accuracy of the proposed inversion procedure.

Keywords: MFL, defect reconstruction, RWBF neural network

DOI: 10.3233/JAE-141865

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 465-471, 2014

Authors: Pelkner, Matthias | Reimund, Verena | Erthner, Thomas | Kreutzbruck, Marc

Article Type: Research Article

Abstract: Their small size together with a remarkable field sensitivity are the most prominent features of present-day GMR sensors paving the way for various applications in automated non-destructive testing (NDT). This work presents a prototype for fast and automated magnetic testing of roller bearings. A local magnetization unit excites the magnetic field inside the bearing. As a result of a design study and the following wafer fabrication the probe was equipped with NDT-adapted GMR sensor arrays in …which 48 elements measures the field response. The detection of artificial and 40 μm deep defects could be resolved with a SNR better than 20 dB. In addition, we report of first results of a POD (Probability of Detection) analysis using GMR sensors to investigate bearings with EDM (electronic discharge machining) notches having depths down to 10 μm. Finally, we estimate successfully the depth of a 57 μm notch from the measured data. Show more

Keywords: Giant magneto resistance, non-destructive testing, magnetic flux leakage, sensor array

DOI: 10.3233/JAE-141866

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 473-479, 2014

Authors: Su, Daniel | Li, Xiang | Luo, Yun

Article Type: Research Article

Abstract: Since the excitement of gecko free-walk on a smooth surface is discovered with the cause of Wan der Waals force, researchers have focused on the development of biomimetic gecko tape. Hierarchical structure and anisotropic adhesion are two of the spotlights. However, little work has been done on integration of these two parameters. This paper presents a model design of orientated micro-and nano-arrays including three levels of setae, branches and spatulae. Finite element method is applied for …compression shear test simulation. The anisotropic property is controllable due to the hierarchical surface design. Show more

Keywords: Hierarchical structure, anisotropic adhesion, micro-and nano-array, seta, spatula, FEA

DOI: 10.3233/JAE-141867

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 481-487, 2014

Authors: Rymarczyk, Tomasz

Article Type: Research Article

Abstract: The electrical impedance tomography is a widely investigated problem with many applications in physical and biological sciences. A new nondestructive method of the flood embankment dampness was tested. The basic information about the built measuring system, including the prototype equipment is given. The setup was used to determine the dampness of the test flood blank on a specially built model. The forward problem solution (in the electrical impedance tomography) is solved by the determining potential distribution …inside the region under given boundary conditions. The full information about region is considered, This problem is solved by Laplace's equation. The level set methods with the Chan-Vese model were applied in the inverse problem for the image reconstruction. Show more

Keywords: Electrical impedance tomography, inverse problem, level set method

DOI: 10.3233/JAE-141868

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 489-494, 2014

Authors: Bouchareb, Ilhem | Bentounsi, Amar | Lebaroud, Abdesselam

Article Type: Research Article

Abstract: In the case of one phase failure, the switched reluctance motor (SRM) will behave nearly the same, both in open circuit and in short circuit failure. This means, that the machine will understand the two faults in the same way which makes the SRM faults detection and diagnosis a more challenging task. This paper presents a diagnosis method based on pattern recognition analysis to detect and to classify automatically the electrical faults, short- and open-circuit under …any level of load of the studied system: redundant three-phase power converter fed 6/4 SRM. The phases making a pattern recognition diagnosis of SRM, the training and the decision. The training phase consists in determining the pattern vector and the optimal kernels design (the separating classes) by Time-Frequency Representation (TFR). The training data is carried out using a set of fault scenarios, between healthy, single and combined faults, in terms of torque measurement at different load level, in order to deduce the fault severity. The second phase, consists in associating an unknown pattern with one of the defined classes, according to the "k-nearest neighbors" (knn) decision rule, associated with Kalman estimator to tracking of various operating modes and to predict the evolution of the call out of the knowledge database for a given operating mode in order to realize a preventive maintenance. The experimental results prove the efficiency of pattern recognition methods in condition monitoring of reluctance machine. Show more

Keywords: Fault detection, automated classification, statistical pattern recognition, Kalman predictor, SRM

DOI: 10.3233/JAE-141869

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 495-502, 2014

Authors: Ahn, Hyun-Mo | Lee, Jong-Deok | Lee, Byuk-Jin | Hahn, Sung-Chin

Article Type: Research Article

Abstract: Recently, permanent magnetic actuator (P.M.A.) is widely used to drive the mechanism of vacuum circuit breaker (V.C.B.). This paper deals with the optimal design of P.M.A. for V.C.B. using the response surface method (R.S.M.). First, the dynamic characteristics of the initial P.M.A. model, such as the holding force, exciting current, and action complete time, are calculated by coupled electrical-mechanical problem based on finite element method (F.E.M.). In order to verify the validity of numerical results obtained …from finite element analysis (F.E.A.), the calculated dynamic characteristics of the initial P.M.A. model are compared with no-load test results. Next, using the R.S.M., the initial P.M.A. model is optimized to improve the dynamic characteristics. Finally, in order to verify the validity of the P.M.A. model optimized by using the R.S.M., the dynamic characteristics of the optimized P.M.A. model are calculated by using F.E.A. and compared with those of the initial P.M.A. model. Show more

Keywords: Finite element analysis, permanent magnetic actuator, response surface method, vacuum circuit breaker

DOI: 10.3233/JAE-141870

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 503-509, 2014

Authors: Wei, Zheng | Huang, Songling | Zhao, Wei | Wang, Shen

Article Type: Research Article

Abstract: In order to meet the engineering requirement of gas pipeline inline inspection for cracking defects, a new ultrasonic guided wave (GW) method based on electromagnetic acoustic transducer (EMAT) has emerged. In consideration of the large amount of original inspection data and the limited capacity of the storing device, the research on rapid and large ratio data compression is needed. This paper proposes a new large ratio data compression method based on subsection adaptive method (SAM) and …wavelet neural network (WNN) algorithm. The influences of parameter selection on the compression quality, speed and ratio and the method of enhancing the compression speed of this method is studied. The experiment results indicate that compared with the traditional WWN compression algorithm, the proposed method has higher compression quality and speed, and a large compression ratio of 110:1 is achieved by the proposed method. It is thus suitable for gas pipeline crack inline inspection based on EMAT-generated GW. Show more

Keywords: EMAT-generated GW inspection, large ratio data compression, subsection adaptive method, WNN algorithm

DOI: 10.3233/JAE-141871

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 511-517, 2014

Authors: Carlstedt, Matthias | Porzig, Konstantin | Uhlig, Robert P. | Zec, Mladen | Ziolkowski, Marek | Brauer, Hartmut

Article Type: Research Article

Abstract: Lorentz force eddy current testing is a novel nondestructive testing technique which can be applied preferably to the identification of internal defects in non-ferromagnetic moving conductors. This paper describes the comparison of this new technique with well-known eddy current testing. Measurements and numerical simulations have been done for both techniques for artificial subsurface defects in a test specimen made of Aluminum alloy moving with constant velocity.

Keywords: Eddy current testing, lorentz force eddy current testing, moving conductors, nondestructive testing

DOI: 10.3233/JAE-141872

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 519-526, 2014

Authors: Psuj, Grzegorz | Chady, Tomasz

Article Type: Research Article

Abstract: Different phases which exist in a duplex stainless steel (DSS) affect mechanical as well as electromagnetic properties. Therefore, an eddy current (EC) technique can be utilized to detect phases inclusions. In order to evaluate and identify the amount of deleterious phases it is important to assess the impact of electromagnetic properties of material on a measuring signal. This paper presents a study on the influence of DSS properties changes caused by a sigma (σ) phase on …signal measured by an EC transducer. The results of an analytical and numerical analysis are presented. The analytical modeling allows to identify the electromagnetic properties and evaluate the amount of σ phase in the tested material. Show more

Keywords: Duplex stainless steel, sigma phase, electromagnetic properties, eddy current testing, analytical and numerical analysis

DOI: 10.3233/JAE-141873

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 527-534, 2014

Authors: Paul, Subhra | Bird, Jonathan Z.

Article Type: Research Article

Abstract: This paper presents a new eddy current modeling approach in which the edge field contribution for a finite width conducting plate is accounted for. The 3-D steady-state analytic eddy current model accounts for the source field contributions from oscillatory as well as translational velocity motional effects. The paper discusses the modeling inaccuracies caused by neglecting the source field contributions on the edges of the conductive plate. The new modeling approach is validated by comparing the analytic …calculations with a 3-D steady-state finite element analysis model. Show more

Keywords: Eddy current, magnetic vector potential

DOI: 10.3233/JAE-141874

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 535-542, 2014