Fatigue Life and Reliability Study on Aviation Engine Blade

Abstract: Aviation engine blade is a major component of the engine and one of the key rotating components, which is charged with the important task of energy conversion.Common factors that lead to blade failure include low cycle fatigue, vibration, buckling, creeping and so on. With the improvement of the modern aviation engine Thrust-Weight Ratio, the design leaves a substantial increase in stress levels, while low-cycle fatigue failure roulette gradually become one of the most important failure mode. Low-cycle fatigue failure mostly occurred in the department where stress concentrated such as the two sides of the blade root where airflow passes in and out.With a combination of theoretical analysis and experimental study methods, here in this paper we studied the blade fatigue reliability analysis methods and the reliability as follows:1. A systematic review over the current widely used methods in estimating the fatigue life and reliability analysis, in order to find out applicable research methods for this text.2. In accordance with national standards we designed the blade material TC4 titanium alloy fatigue test and through this test we get a series of Mechanical properties of the materials, including the S-N curve, theσ?εcurve which lay the foundation for the future fatigue life estimate and reliability analysis of fatigue.3. Established the finite element model of the blade, and conduct the transient analysis on specific conditions. By analyzing the results of the stress response we defined the dangerous fatigue parts, and get the blade course load at the same time, which make preparations for the estimating of fatigue life.4. Joint with the results of fatigue test and finite element analysis, using Nominal Stress Method and Miner’s Linear Damage Accumulation criteria, and utilizing the fatigue analysis software we made the life-wide analysis of the blade and got Fatigue damage nephogram and age distribution. On this account we identified the department where failure may occur and defined it match the actual result after comparison.5. Analysis the reliability in the light of Stress-Intensity Interference Model and define the reliability of the blade.Blade is also a key point for the aero-engine safety. It has a decisive impact on the reliability of the entire device. Therefore the study on aero-engine blade fatigue life and reliability has important study significance and great engineering application values…
Key words: “Blade”; “Endurance Test”; “Nominal Stress Method”; “Miner’s Linear Damage Accumulation”; “Stress– Intensity Interference Model”; “Finite Element Analysis”

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