Research On Life Estimation Method Of Aeroengine Turbine Rotor

Turbine rotor structure comprising blade, disk and tenon / mortise connecting structure, is one of the most important structure on aircraft engine. It is a typical kind of hot-end components, which works at high temperature and high load environment. The reliability and structural integrity of turbine is of great significance in terms of the engine. According to design characteristics and the working environment for turbine rotor structure, combining latest research result on life assessment, this paper studied the life estimation method of turbine rotor structure, as follows:1. The basic theory of low-cycle fatigue and life prediction methods was researched. According to the meaning and processing methods of fatigue load spectrum,the paper took the local stress-strain analysis as the main research object, and defined the basic principle, calculation process and scope of application of this method.2. In the turbine blades as the main target, which always face high-cycle-fatigue, the paper studied the high cycle fatigue theory and life estimation methods. First, the resonance analysis method of the blade was introduced. Second, on the basis of the material on the S-N curve, the life assessment method under constant amplitude loading of high cycle fatigue was determined. Finally, further information on the fatigue damage accumulation theory under complex loads was also put forward.3. According to the working environment of hot-end components, the creep rupture life analysis method was proposed. The basic concepts of creep and creep life analysis method were introduced, and with domestic and international experience in the development of the engine, the design requirements and methods for anti-creep of turbine structure were also proposed.4. For a small turbofan engine, using 3D FSI method to analyze the temperature distribution of turbine structure. The turbine structure were modeled integrated through FEM method, and the stress-strain of structure was calculated by plastic finite element method. The creep life of turbine was evaluated by using Larson-Miller equation and low cycle fatigue life was evaluated by Manson Coffin equation. The impact of high cycle fatigue was also analyzed according to resonance analysis of blade. The results show that tongue and teeth are the weakness location of turbine rotor, and defines 102 times of duty cycle as the life expectancy of the whole structure.