PSI - Issue 35

ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000 Structural Integrity Procedia 00 (2019) 000 – 000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com Sci nceDir t Available online at www.sciencedirect.com ScienceDirect

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

Procedia Structural Integrity 35 (2022) 74–81

© 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of IWPDF 2021 Chair, Tuncay Yalçinkaya Abstract Vibration diagnostics of damage belongs to the class of non-destructive methods, which usually do not take long time. However, the main problem of vibration diagnostics is relatively low sensitivity to the critical damage of fatigue crack type, which arises because of long time accumulation of plastic deformation. To improve the sensitivity and reliability of vibration diagnostics of damage two methods were considered. The first method was based on the fact, that a characteristic feature of vibrations of structural elements with fatigue crack is the occurrence of non-linear resonances (sub- and super-harmonic) and significant non linearity of vibration response at these resonances. The second one – on the fact, that quite noticeable in certain cases increase of damping characteristic caused by a crack can be observed. Analytical and experimental studies of these methods were carried out as applied to the blades of aircraft gas turbine engines. As a result of the studies, the intensity of change in parameter of super harmonic resonance and in damping characteristics at different parameters of crack was determined. Besides, the experimental techniques for vibration testing of turbine blades were developed. There was demonstrated, that the sensitivity of both considered methods of vibration diagnostics is several orders of magnitude higher than the sensitivity of conventional methods based on the change in natural frequencies and mode shapes, and they can be effectively used for the diagnostics of blades on the stage of engine repair. © 2021 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of IWPDF 2021 Chair, Tuncay Yalçinkaya Keywords: Damage detection; super-harmonic resonance; damping characteristic; aircraft gas turbine engine; blades. 2nd International Workshop on Plasticity, Damage and Fracture of Engineering Materials Highly sensitive methods for vibration diagnostics of fatigue damage in structural elements of aircraft gas turbine engines A. Bovsunovsky a, *, O. Nosal a a National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute", Prosp. Peremohy, 03056, Kyiv, Ukraine Abstract Vibration diagnostics of damage belongs to the class of non-destructive methods, which usually do not take long time. However, the main problem of vibration diagn stics is r latively low sen itivity to the critical damage of fatigue crack type, which aris s because of l ng time accumulation f plastic deformati n. To improve the sensitivity and r liability of vibration diagnostics of damag two methods were considered. The first eth d was based on the fac , that a char cteristic feature of vibration structural ele nts with fatigue crack is the occurrence f non-linear resonances (sub- and super-harmonic) and sign ficant non linearity of vibration response at these resonan es. Th second o – on the fa t, that quite noticeable in cert i cases in rease of damp ng characteristic caused by a crack can be observed. A alytical a d xperimen al s udies of th se m thods were car ied out as a plied to the blades of aircraft gas turbi e ngines. As a result of the studies, the in ensity of change in parameter of super harmonic resonance and in dampin cha act ristics at different paramet r of crack was determined. B s des, the experimental techniques for vibratio testing of turbine blade were developed. Ther was demonstrated, that the sensitivity of both considered methods of vibration diagnostics is several or rs of magnitud hig than th se itivity of conventional methods based on the change in natu l frequencies and mode shapes, and they can be effectively us d for the diag ostics of blades on the stage of engine repair. © 2021 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review u der re ponsibility of IWPDF 2021 hair, Tu cay Yalçinkay K ywords: Damage detection; super-harmonic resonance; d mping characteristic; aircraft gas turbine engine; blades. 2nd International Workshop on Plasticity, Damage and Fracture of Engineering Materials Highly sensitive methods for vibration diagnostics of fatigue damage in structural elements of aircraft gas turbine engines A. Bovsunovsky a, *, O. Nosal a a National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute", Prosp. Peremohy, 03056, Kyiv, Ukraine

* Corresponding author. Tel.: +380-63-252-9878. E-mail address: apbovsunovsky@gmail.com * Corresponding author. Tel.: +380-63-252-9878. E-mail address: apbovsunovsky@gmail.com

2452-3216 © 2021 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of IWPDF 2021 Chair, Tuncay Yalçinkaya 2452-3216 © 2021 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review u der responsibility of IWPDF 2021 hair, Tuncay Yalçinkay

2452-3216 © 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of IWPDF 2021 Chair, Tuncay Yal ç inkaya 10.1016/j.prostr.2021.12.050