Signal processing for non-contact NDE

• Autorzy: Kubinyi M. , Docekal A. , Ramos H. , Ribeiro A.

Warianty tytułu

PL

Przetwarzanie sygnałów w defektoskopii bezkontaktowej

• Języki publikacji: EN

Abstrakty

EN

The detection of defects in aerospace structures with non-destructive techniques is an important requirement for quality checks not only during production phase but mainly during in-service maintenance operations. Visual inspection allows only the analysis of surface characteristics of materials. A deeper analysis is required for the characterisation of the widest defects types such as subsurface corrosion or cracks. For aerospace structures inspection, two different methods are mainly used: eddy current and ultrasonic testing. The first method is based on the induction of currents in the electrically conducting material to be tested. The perturbations of the eddy-current flow path due to physical, structural or metallurgical inhomogeneities are detected either using coils or magnetic field sensors. The second method uses high frequency sound waves which are sent into the tested object. A probe picks up the reflected waves and analysis of the received signal is done to locate flaws in the tested object. Ultrasonic inspection can detect defects such as cracks and discontinuities mainly inside the studied object. In this paper both techniques are addressed in order to conclude the different detection performances of these non-destructive inspection methods using different industrial and experimental probes. Two different eddy current probes were projected and implemented. One includes an excitation coil and two differential detection coils. Another having a similar excitation coil to generate the eddy currents in the material to be tested but using a Giant Magneto-Resistor (GMR) to asses the magnetic field induced. Both probes were tested with an aluminum standard airframe plate sample with and a dedicated data acquisition measuring system. This sample was also inspected using a certified industrial Eddy Current system. The ultrasonic method was tested using an Electromagnetic Acoustic Transducer (EMAT) probe and multidimensional signal processing. The same measurements performed with the experimental Eddy Current system were carried out with industrial piezoelectric ultrasonic transducers.

PL

Wykrywanie defektów w przemyśle lotniczym ma stawia wysokie wymagania zarówno na etapie produkcji jak i serwisowania. Żąda się aby było możliwe wykrywanie niewidocznych defektów, jak korozja czy pęknięcia. W przemyśle lotniczym stosowane są dwie główne metody inspekcji prądów wirowych i ultradźwiękowa. W pierwszej metodzie zmiany pola magnetycznego wykrywane są za pomocą cewki lub czujnika pola magnetycznego. W drugiej metodzie czujnik wykrywa falę odbitą. Metoda ultradźwiękowa pozwala na wykrycie pęknięć wewnątrz materiału. W prezentowanym artykule obie metody są analizowane. Zaprojektowano i zbadano dwa różne czujniki możliwe do zastosowania w metodzie prądów wirowych. Pierwszy z nich składa się z cewki magnesującej i dwóch cewek różnicowych. W drugim cewki różnicowe zastąpiono czujnikiem magnetorezystancyjnym GMR. Oba czujniki testowano na podłożu aluminiowym. W metodzie ultradźwiękowej testowano elektromagnetyczny czujnik akustyczny EMAT oraz wielowymiarowe przetwarzanie sygnału. Wyniki testów weryfikowano stosując czujnik piezoelektryczny.

Słowa kluczowe

EN

eddy current inspection; experimental probes; EMAT; ultrasonic inspection; thin material

PL

defektoskopia wiroprądowa; defektoskopia ultradźwiękowa; czujnik magnetorezystancyjny

• Wydawca: Wydawnictwo SIGMA-NOT
• Czasopismo: Przegląd Elektrotechniczny
• Rocznik: 2010
• Tom: R. 86, nr 1
• Strony: 249--254
• Opis fizyczny: Bibliogr. 12 poz., il., rys., wykr.

Twórcy

autor

Kubinyi M.

autor

Docekal A.

autor

Ramos H.

autor

Ribeiro A.

• Czech Technical University in Prague,

Bibliografia

• [1] D. Balageas, C-P Fritzen, A. Guemes: Structural Health Monitoring, Wiley, pp. 13-15. 2006
• [2] M. Buonsanti, M. Cacciola, S. Calcagno, F. C. Morabito, M. Versaci: Ultrasonic Pulse-Echo and Eddy Current Testing for Detection, European NDT Conference, pp. 123-134. 2006
• [3] B.P.C. Rao: Practical Eddy Current Testing, Narosa, pp. 31-47. 2007
• [4] J.R. Brencea, D.E. Brown: Data Mining Corrosion from Eddy Current Non-Destructive Tests, Computer & Industrial Engineering 43, pp. 821-840. 2002
• [5] P.M. Ramos, A.C. Serra: A New Sine-fitting Algorithm for Accurate Amplitude and Phase Measurements in Two Channel Acquisition Systems, Measurements 41, pp. 135-143. 2008
• [6] H.G. Ramos, A.L. Ribeiro, T. Radil, M. Kubínyi, M. Paval: Signal Processing in an Eddy Current Non-Destructive Testing System, 16th IMEKO TC4 Symposium, pp. 223-228. 2008
• [7] R. Smid, A. Docekal, M. Kreidl: Automated Classification of Eddy Current Signatures During Manual Inspection, NDT&E International 38, pp. 462-470. 2005
• [8] A. Docekal, M. Kreidl, R. Smid: Novel Method for 3D Visualisation of Detected Flaws During Eddy Current Inspection, NDT Welding Bulletin 1, pp. 18-21. 2006
• [9] O. Postolache, M.D. Pereira, H.G. Ramos, A.L. Ribeiro: NDT on Aluminium Aircraft Plates based on Eddy Current Sensing and Image Processing, IEEE Instrumentation and Measurement Technology Conference, pp. 1803-1808. 2008
• [10] J. Madsen, E.G. Lightsey: Attitude Determination Using GPS Signal to Noise Ratio and Carrier Phase Measurements, AIAA Guidance, Navigation, and Control Conference, pp. 212-219. 2003
• [11] V. Matz, M. Kreidl, R. Smid, S. Starman: Comparison of Denoising Methods Used for EMAT Signals, European NDT Conference, pp. 1.3.5. 2006
• [12] K.F. Graff: Wave Motion in Elastic Solids, Dover Publications, pp. 213-257. 1991