The concept of condition-based gas turbine-powered aircraft operation is realized all over the world, which implementation requires knowledge of the end-of-life information related to components of aircraft engines in service. This research proposes an algorithm for estimating the equivalent cyclical running hours. This article provides analysis of the existing methods of cycle counting and suggests a new original method. It implies consideration of two cycles related to the chain of extrema “max - min – max”. The first is the main simple loading cycle; another cycle is the additional from the minimum to the lowest extrema. It is assumed that the "global" minimum is known. The authors developed the algorithm aiming at allocation of separate simple loading cycles in a complex life cycle, implemented by using Visual Basic for Applications and Excel’97. The paper also provided the method of bad records rejection and evaluation of the stress-strain behavior of the main engine components – drive shafts, discs and blades based on regular measurements of temperature and pressure in the gas stream. These methods allow calculating the accumulation of damage on a real-time basis. The developed algorithms laid the foundation for an automated diagnostic system of an aircraft engine.

Aronson, A. (1990). The impact of polyharmonic loading on durability and fatigue resistance in corrosive medium. Problems of Strength, 7, 45-48.

Astafiev, V. I., Fedorchenko, D. G. & Tzypkaikin, I. N. (1996). Complex stress-time cycles influence on aircraft engine parts fatigue strength. Proceedings of the Sixth International Fatigue Congress, 96, 499-504.

Baklacioglu, T., Onder T., & Hakan A. (2015). Dynamic modeling of energy efficiency of turboprop engine components using hybrid genetic algorithm-artificial neural networks. Energy, 86, 709-721.

Bartelds, G. (1997). Aircraft Structural Health Monitoring, Prospects for Smart Solutions from a European Viewpoint. Structural Health Monitoring, Current Status and Perspectives, 293–300.

Birger, I. A. (1984). Strength calculation of the aircraft gas-turbine engines. Moscow: Engineering, 208 p.

Coffin, L. F. (1976). The Prediction of Wave Shape Effect in Time-Dependent Fatigue. Proceeding on the 2 International conference on Behavior of Materials, 866-870.

Cowan, R. S., & Winer, W. O. (1999). Research Developments in Integrated Diagnostics and Prognostics. Structural Health Monitoring, 237–246.

Falaleev, S., Chaadaev, K. & Diligenskiy, D. (2014).Selection of the hydrodynamic damper type for the turbomachine rotor. Life Science Journal, 11(7), 502-505.

Fedorchenko, D. G. (2014). Simulation of real loading conditions in designing the high-durability turbo machines using high-level models. Bulletin of Irkutsk State Technical University, 6, 78-86.

Fedorchenko, D. G. (2015). Development of methods and systems of GTE end-of-life control in operation. Bulletin USATU, 19(1-67), 55-61.

Hached, S. (2014). Novel, remotely controlled, artificial urinary sphincter: A retro-compatible device. Transactions on Mechatronics, 19(4), 1352-1362.

Harvey, D. Y. (2015). Structural Health Monitoring Software for Aerospace, Civil, and Mechanical Infrastructure. Los Alamos: Los Alamos National Laboratory, 266 p.

Herrera, C., Yepifanov, S., & Loboda, I. (2011). A comparative analysis of turbine rotor inlet temperature models. Proceedings of ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 3, 317-327.

Kogayev, V. P., & Drozdov Y. N. (1991). Strength and durability of machine parts. Moscow: Higher school, 319 p.

Krivenyuk, V. (2009). Forecasting the Long-Term Strength of Heatproof Nickel Alloys. Metal and Casting in Ukraine, 11(12), 20-25.

Kudva, J., Grage, M., & Roberts, M. (1999). Aircraft Structural Health Monitoring and Other Smart Structures Technologies-Perspectives on Development of Future Smart Aircraft. Palo Alto: Technomic Publishing. Structural Health Monitoring, 106–119.

Kulyk, M., Kucher, O., & Miltsov, V. (2011). Mathematical models of the calculation of aircraft structural reliability. Aviation, 15(1), 11-20.

Kuznetsov, N. D. (1989), Engineering methods of aeroelastic phenomena study at turbomashinery vibration development. Proceedings of International conference on Engineering aero-hydroelectricity, 405 – 409.

Mouhat, O., Khamlichi, A., & Limam, A. (2015). Reliability analysis of buckling limit state for friction stir welded aircraft stiffened panels. Key Engineering Materials, 640, 35-42.

Novikov, D. (2014). Development of Squeeze Film Damper Characteristics Calculation Methods Which Take into Account a Liquid Inertia Forces. Research Journal of Applied Sciences, 9(10), 649-653.

Tzeytlin, V. I., & Fedorchenko D. G. (1980). Assessment of component durability under the combined impact of repeated static and vibration loading. Problems of Strength, 1, 14-17.

Varadan, V. K., & Varadan, V. V. (1999). Wireless Remotely Readable and Programmable Microsensors and MEMS for Health Monitoring of Aircraft Structures. Palo Alto:Technomic Publishing. Structural Health Monitoring, 96–105.

Vronsky, G. ( 2004). Modified complete cycle method and schematization of multidimensional loading processes. TsAGI Scientific Notes, 35(1-2), 97-109.

Wiseman, M. W., & Guo, T. H. (2001). An investigation of life extending control techniques for gas turbine engines. Proceedings of the IEEE American Control Conference, 5, 3706-3707.

Yepifanov, S. V., Ring, N. A., Glikson, I. L. & Shankin, S. I. (2013) Modernization of the "rain" method for the end-of-life monitoring of GTE main components. Aerospace Engineering and Technology, 9(106), 173-176.