volume | PIER Journals

Abstract

Reliable performance of a component or structure depends on its pre-service quality and in-service degradation under operating conditions. The importance of Non-Destructive Testing and Evaluation is ever increasing, above all in ensuring pre-service quality and monitoring in-service degradation, in order to avoid premature failure of the components/structures. There are many Non-Destructive Techniques based on various physical principles. In this work, our main objective is the characterization of anomalies such as defects, stresses and microstructural degradations in materials. Particularly, in this work we propose a Finite Element Method based approach for modelling a fast and accurate evaluation of defects in metallic materials able to easily detect defects, aside from the orientation. Within this framework, the paper proposes the application of a magnetic field rotating perpendicularly to the analysed specimen. We discuss a few case studies, starting from numerical simulations and finally highlighting the importance of this approach in order to evaluate the structural integrity assessment.

1. Grimberg, R., I. Olteanu, T. Cristea, M. Goia, D. Gradinariu, R. Plavanescu, T. Bacanu, A. Andreescu, and D. Apavaloaie, "Eddy current examination of steel wires," NDT Int., Vol. 23, No. 4, 201, 1990.
doi:10.1016/0308-9126(90)91602-P

2. Grimberg, R., A. Savin, O. Mihalache, N. Rezlescu, E. Bradu, S. Chifan, V. Iftimi, and A. Andreescu, "Reliability of automatic eddy-current equipment with a rotating magnetic field," NDT and E International, Vol. 28, No. 5, 297-301, 1995.
doi:10.1016/0963-8695(95)00013-N

3. Tagaki, T., H. Huang, H. Fukutomi, and J. Tani, "Numerical evaluation of correlation between crack size and eddy current testing signals by a very fast simulator," IEEE Transactions on Magnetics, Vol. 34, 2582-2584, 1998.

4. Nevels, R., J. Miller, and J. Miller, "Rotation in electromagnetic field equations: A discussion, interpretation and application," IEEE Transactions on Magnetics, Vol. 2, 875-878, 1998.

5. Specogna, S. and F. Trevisan, "Voltage Driven coils within a discrete geometric approach to 3D eddy-currents," Proceedings of 11th IGTE Symposium on Numerical Fields Calculation, 81-84, 2004.

6. Tonti, E., "Algebric topology and computational electromagnetism," Proceedings 4th Int. Workshop Electric Magnetic Fields, 284-294, 1998.

7. Dodd, C. V. and W. E. Deeds, "Analytical solutions to eddycurrent probe-coil problems," J. Appl. Phys., Vol. 39, 2829-2838, 1968.
doi:10.1063/1.1656680

8. Lewis, A. M., "A theoretical model of the response of an eddycurrent probe to a surface-breaking metal fatigue crack in a flat test piece," J. Phys. D: Appl. Phys., Vol. 25, 319-326, 1992.
doi:10.1088/0022-3727/25/2/030

9. Ferraris, G., "Rotazioni elettrodinamiche prodotte per mezzo di correnti alternate," Atti dell'Accademia delle Scienze di Torino, Vol. 23, 360, 1888 (in Italian).

10. Rodger, D., P. J. Leonard, and H. C. Lai, "Interfacing the general 3D A-ψ method with a thin sheet conductor model," IEEE Transactions on Magnetics, Vol. 28, No. 2, 1115-1117, 1992.
doi:10.1109/20.123879

11. Tsuboi, H. and T. Misaki, "Three dimensional analysis of eddy current distribution by the boundary element method using vector variables," IEEE Transactions on Magnetics, Vol. 23, 3044-3046, 1987.
doi:10.1109/TMAG.1987.1065434

12. Weissenburger, W. D. and U. R. Christensen, "A network mesh method to calculate eddy currents on conducting surfaces," IEEE Transactions on Magnetics, Vol. 18, No. 2, 422-425, 1982.
doi:10.1109/TMAG.1982.1061879

13. Tober, G. and T. Meie, "Corrosion inspection in aircraft construction," Zeitschrift Materials and Corrosion, Vol. 46, 405-409, 1995.
doi:10.1002/maco.19950460704

14. Bischoff, W., H.-A. Crostack, and M. Maass, "CS-pulsed eddy current inspection for cracks in multi-layered joint al-alloy aircraft structures," The E-Journal of Nondestructive Testing & Ultrasonics, Vol. 3, No. 9, 1998, available online at http://www.ndt.net/article/ecndt98/aero/055/055.htm, January 31st, 2008.

15. Weisteinn, W., "Euler angles," MathWorld, A Wolfram Web Resource, available online: http://mathworld.wolfram.com/ EulerAngles.html.

16. Dodd, C. V. and W. E. Deeds, "Analytical solutions to eddy-current probe-coil problems," Journal of Applied Physics, Vol. 39, 2829-2838, 1968.
doi:10.1063/1.1656680

17. Lewis, A. M., "A theoretical model of the response of an eddy-current probe to a surface-breaking metal fatigue crack in a flat test piece," NDT and E International, Vol. 25, 319-326, 1992.

18. Tsuboi, H. and T. Misaki, "Three dimensional analysis of eddy current distribution by the boundary element method using vector variables," IEEE Transactions on Magnetics, Vol. 26, No. 2, 454-457, 1990.
doi:10.1109/20.106351

19. Weissenburger, D. W. and U. R. Christensen, "A network mesh method to calculate eddy currents on conducting surfaces," IEEE Transaction on Magnetics, Vol. 18, No. 2, 422-425, 1982.
doi:10.1109/TMAG.1982.1061879

Dr. Matteo Cacciola

Dr. Diego Pellicano

Dr. Giuseppe Megali

Prof. Salvatore Calcagno

Prof. Francesco Carlo Morabito