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The formation and analysis of eddy current probe signals obtained in pulsed excitation mode is considered. The proposed method of implementing pulsed eddy current testing with the formation of attenuating harmonic oscillations is more resistant to the effects of noise and interference that accompany the process of inspected object parameters evaluation. The equivalent scheme of the system test object eddy current probe is developed and analyzed. The obtained mathematical model of the eddy current probe signals allowed proposing the natural frequency and the attenuation as informative signals parameters, which are determined from signals phase and amplitude characteristics. Developed algorithm and the proposed methodology was implemented for evaluation of eddy current signals parameters and related characteristics of testing objects. This method was experimentally verified on a series of different test specimens. The obtained results confirm the possibility to apply the proposed informative signals to solve some problems concerned with automated eddy current testing. The formation and analysis of eddy current probe signals obtained in pulsed excitation mode are considered. The proposed method of implementing pulsed eddy current testing with the formation of attenuating harmonic oscillations is more resistant to the effects of noise and interference that accompany the process of automated eddy current testing. The equivalent scheme of the system test object eddy current probe is developed and analyzed. The obtained mathematical model of the eddy current probe signals allows proposing the natural frequency and the attenuation as informative signals parameters, which are determined from signal phase and amplitude characteristics. Methods of increasing the accuracy of determining the eddy current probe signals attenuation and frequency using trends of signals phase and amplitude characteristics are considered. The proposed signal processing method was verified by modeling the process of determining the eddy current probe signals attenuation and the frequency from the signal with Gaussian noise. Algorithmic and software were developed based on the simulation results and the proposed improved methodology was implemented for determining signals parameters and related parameters and characteristics of testing objects.

1. Libby, H.L. Introduction to Electromagnetic Nondestructive Test Methods, Wiley-Interscience New York, 1971.

2. Dorofeev, A.L .; Kazamanov, Yu.G. Electromagnetic defectoscopy; Mashinostroienije, 1980. (in Russian)

3. Non-destructive testing. In 5 books. Book. 3. Electromagnetic control: A practical guide. Sukhorukov, V.V., Eds.; Vysshaya shkola, 1992. (in Russian)

4. Teterko, A.Ya .; Nazarchuk, Z.T. Selective eddy current defectoscopy, Karpenko Physico-Mechanical Institute of the NAS of Ukraine, Lviv, 2004. (in Ukrainian)

5. Uchanin, V.; Ostash, O.; Bychkov, S.; Semenets, O.; and Derecha, V. Eddy current monitoring of aluminum alloy degradation during long-term operation of aircraft, The Paton welding Journal, 2021, 8, 45-51. https://doi.org/10.37434/tpwj2021.08.09

6. Vasic, D.; Bilas, V.; and Ambrus, D. Pulsed Eddy-Current Nondestructive Testing of Ferromag netic Tubes, IEEE Trans. Instrum. Meas., 2004, 53 (4), 1289-1294. https://doi.org/10.1109/TIM.2004.830594

7. Thyagarajan, K.; Maxfield, B.; Balasubramaniam, K.; and Krishnamurthy, C.V. Pulsed Eddy Current Imaging of Corrosion Pits, J. Nondestructive Testing & Evaluation, 2008, 7(2), 32-36.

8. Cadeau, T.; Krause, T. Pulsed eddy current probe desing based on transient circuit analysis, Review of Progress in Quantitative NDE, 2009, 28, 327-334. https://doi.org/10.1063/1.3114222

9. Bieber, J. A.; Tai, Cheng-Chi; and Moulder, J. C. Quantitative Assentment of Corrosion in Aircraft Structures Using Scanning Pulsed Eddy Current, Review of Progress in Quantitative Nondestructive Evaluation, 1998, 17. https://doi.org/10.1007/978-1-4615-5339-7_40

10. Plotnikov, Y.; Bantz W. Subsurface defect detection in metals with pulsed eddy current, Review of Progress in Quantitative NDE, 2005, 24, 447-454. https://doi.org/10.1063/1.1916710

11. Angani, C.S.; Ramos, H.G.; Ribeiro, A.L.; Rocha, T.J.; and Baskaran, P. Transient eddy current oscillations method for the inspection of thickness change in stainless steel, Sensors and Actuators A: Physical, 2015, 233, 217-223. https://doi.org/10.1016/j.sna.2015.07.003

12. Angani, C.S.; Ramos, H.G.; Ribeiro, A.L.; Rocha, T.J.; and Baskaran, P. Lift-Off Point of Intersection Feature in Transient Eddy-Current Oscillations Method to Detect Thickness Variation in Stainless Stee, IEEE Transactions on Magnetics, 2016, 52(6), 1-8. https://doi.org/10.1109/TMAG.2016.2531024

13. Buchma, I.M.; Repetylo, T.M .; Ferchuk, K.V. Means of eddy current diagnostics of corrosion condition of steel sheet structures; Lviv Polytechnic National University, 2015. (in Ukrainian)

14. Korn,G.; Korn, T. Handbook on Mathematics for Scientists and Engineers, M.: Nauka, 1977. (in Russian)

15. Bendat, J.S.; Piersol, A.G. Random Data. Analysis and Measurement Procedures (4th ed), John Wiley & Sons, INC, Hoboken, New Jersey, 2010. https://doi.org/10.1002/9781118032428

16. Lysenko, Iu.; Eremenko, V.; Kuts, Yu.; Protasov, A.; Uchanin, V. Advanced Signal Processing Methods for Inspection of Aircraft Construction Materials, Transactions on Aerospace Research, 2020, 2(259), 27-35. https://doi.org/10.2478/tar-2020-0008

17. Kuts, Yu.; Lysenko, Iu.; Protasov, A.; Uchanin, V.; and Redka, V. Enhanced Feature Extraction Algorithms Using Oscillatory-Mode Pulsed Eddy Current Techniques for Aircraft Structure Inspection, Transactions on Aerospace Research, 2021, 3(264), 1-16. https://doi.org/10.2478/tar-2021-0013