Application of bispectral analysis of vibroacoustic signals for diagnosis blades cracks in aircraft engines

Authors

DOI:

https://doi.org/10.20535/1810-0546.2015.6.56652

Keywords:

Signal processing, Vibroacoustical diagnosis, Gas-turbine engine, Crack-like damage

Abstract

Background. The work is devoted to vibroacoustical diagnosis of the crack-like damages of the gas-turbine engines (GTE) blades at the steady-state modes of GTE.

Objective. The effectiveness of the usage bispectrum analysis is investigated for signal processing at the vibroacoustical diagnostic of the blades cracks of aviation gas-turbine engines.

Methods. Bispectral analysis is used for diagnostic information processing. Bispectrum can be found using Fourier transform third-order autocorrelation functions:

\[S_{3x}(f_{1},f_{2})=\sum_{k,l=-\infty }^{\infty}C_{3x}(k,l)\textrm{exp}(-j2\pi f_{1}k)\textrm{exp}(-j2\pi f_{2}l).\]

Results. Simulation bispectrum analysis vibroacoustical signals, radiated by models blades of working wheels without crack and with crack at the stationary vibrating excitations are carried out and investigated. It demonstrates that  appearence and evolution of the fatigue crack in a blade increases intensity of bispectral modules.

Conclusions. Application of a modern signal processing methods allows to detect fault features, which are sensitive to small crack-like damages. The receive results can be used to create a vibroacoustical monitoring system for aircraft engine rotor components.

Author Biography

Юрій Валерійович Сопілка, NTUU KPI

Iurii V. Sopilka,

senior lecturer at the Department of devices and systems of attitude and navigation of the Faculty of Instrumentation Engineering

References

I.V. Egorov et al., Information Technology in the Diagnosis of the Technical State of GTE. Moscow, Russia: Torus Press, 2011, 368 p. (in Russian).

N.І. Bouraou, “About the newtendencies of the development of vibroacoustical diagnostics methods of rigidity faults of the gas-turbine engines blades”, Vibratsii v Tekhnike i Tekhnologiyakh, no. 4(20), pp. 45–48, 2001 (in Russian).

N.І. Bouraou,“The aircraft gas-turbine engine dynamic model is proposed for the usage at the vibroacoustical diagnosis of the blades fatigue cracks”, Vibratsii v Tekhnike i Tekhnologiyakh, no. 1(17), pp. 28–32, 2001 (in Russian).

N. Bouraouand and Iu. Sopilka, “Vibroacoustical diagnosis of the crack-like damages of aircraft engine blades at the steady-state and non-steady-state modes”, Vibrations in Physical Systems, vol. 24, pp. 69–74, 2010.

J. Bendat and A. Piersol, Applied Analysis of Random Data. Moscow, USSR: Mir, 1983, 540 p. (in Russian).

N.I. Bouraou et al., Methods of Digital Signal Processing for Vibroacoustic Diagnostics of Aircraft Engines. Кyiv, Ukraine: NAU, 2012, 152 p. (in Ukrainian).

N.I. Bouraou, Non-Stationary Oscillations of Nonlinear (Piecewise Linear) Systems. Kirovograd, Ukraine: Polimed-Servis, 2009, 104 p. (in Ukrainian).

Published

2016-02-25

Issue

Section

Art