International Journal of Applied Electromagnetics and Mechanics - Volume 28, issue 1-2

Authors: Cacciola, Matteo | Deng, Yiming | Morabito, Francesco C. | Udpa, Lalita | Udpa, Satish | Versaci, Mario

Article Type: Research Article

Abstract: Magneto Optic Imaging is a relatively recent Non Destructive Evaluation technique, successfully used to evaluate the integrity of metallic parts in aging aircrafts. In this paper, the authors deal with the implementation of a suitable procedure able to recognize flawed rivets in Magneto Optic measurements. They have been carried out at the NDE Lab, Michigan State University, USA. Exploiting Fuzzy Subtractive Clustering in order to implement the classifier, our proposed approach retrieves a fast and robust …applicative, useful for real-time applications. Preliminary results are really encouraging. Show more

Keywords: Magneto optic images, fuzzy clustering, flawed rivet identification

DOI: 10.3233/JAE-2008-988

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 297-303, 2008

Authors: Kumar, Mrityunjay | Ramuhalli, Pradeep

Article Type: Research Article

Abstract: Data fusion techniques have been used extensively in several application areas, including nondestructive evaluation (NDE) applications. This paper proposes a probability density based pixel-level fusion algorithm for NDE applications. The proposed approach models the fusion process as a convex combination of input data. The model parameters are estimated by optimizing the Kullback-Leibler distance between the density functions of the fused and the input data. Preliminary results on multimodal eddy current NDE data from …aircraft lap joints indicate the feasibility of the proposed approach. Show more

Keywords: Image fusion, aircraft lap joint, pixel-level fusion

DOI: 10.3233/JAE-2008-989

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 305-311, 2008

Authors: Demachi, Kazuyuki | Rybalko, Sergei | Yusa, Noritaka

Article Type: Research Article

Abstract: This paper proposes the method to detect and diagnose the defects of the rotating wings of turbines, pumps and motors by the measuring the change of the eddy currents comparing with those of no defects. The eddy current is induced in the conductor wings rotating in the static magnetic field and the magnetic field by the eddy current is measured by a pick-up coil. The magnetic field are obviously different between the wings with/without the defects. This …method has the possibility of contribution to the earlier findings of the defects of the abnormality of the turbines, pumps and motors. Moreover, the time-series of the horizontal displacement of the rotating axis was measured by the laser displacement meter. To the axis, the external magnetic force was applied by a ring magnet to make the unstable state. The SSA (Singular Spectrum Analysis) [2] was applied to analyze the time-series of the displacement in the unstable state and it was shown that some of the SSA components are sensitive enough for the earlier detection of the transition to the unstable state. Show more

Keywords: Eddy current, diagnosis method, singular spectral analysis

DOI: 10.3233/JAE-2008-990

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 313-320, 2008

Authors: Calcagno, S. | Cardelli, E. | Faba, A. | Formisano, A. | Martone, R. | Morabito, F.C. | Papais, M. | Pirani, A. | Ricci, M. | Specogna, R. | Tamburrino, A. | Trevisan, F. | Versaci, M. | Ventre, S.

Article Type: Research Article

Abstract: The AMDE project ("Applicazioni di Metodi per Diagnostica Elettromagnetica", in English "Applied Methods for Electromagnetic Evaluation") is an Italian two-years national granted research project on electromagnetic non-destructive evaluation. This project involves five different research units located in Italy, about twenty researchers and ten among Ph.D. students and post-doc. Here we focus on the contribution of the AMDE project to the reconstruction of 3D volumetric defects in metallic plates as those used in …aeronautical and aerospace industry. In particular, in this work we propose an efficient numerical model for evaluating the field due to volumetric anomalies and an inversion method based on the Total Variation Regularization. Numerical examples confirm the capability of the proposed strategy to reconstruct 3D volumetric defects. Show more

Keywords: Eddy current testing, numerical methods, total variation regularization, inverse problems

DOI: 10.3233/JAE-2008-991

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 321-327, 2008

Authors: Tamburrino, A. | Ventre, S. | Ferrigno, L. | Udpa, S.

Article Type: Research Article

Abstract: The aim of this work is to describe an eddy current non-destructive testing system employing Giant Magnetoresistive (GMR) sensors. GMR sensors are solid state devices capable of measuring the magnetic flux density. The use of GMR sensors in the framework of eddy current testing is motivated by their intrinsically high sensitivity, large bandwidth and low cost. This paper is specifically focused on the development of a GMR based probe integrated into an eddy current testing system …for detecting the presence of millimeters size cracks in highly conductive materials such as Aluminum. Show more

Keywords: Eddy current testing, giant magneto resistance

DOI: 10.3233/JAE-2008-992

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 329-336, 2008