Life Prediction And Analysis Of A Turbofan Engine Turbine Blade

Turbine blades are one of the key parts and components, which convert one form of energy into another. When aero engine is in service, turbine blades work under temperature load and aerodynamic load besides mechanical load. As the typical hot end component, the turbine blades’ failure often causes disastrous consequences, so they are classified as fracture critical parts. The main failure modes of the blades are low cycle fatigue and creep. As the high-thrust-weight ratio and performance of aero engine become higher and higher, the working conditions of turbine blades are harder and harder, so the reliability should be better and better. In order to ensure the reliability and stability of the engine, it is very necessary to predict the life of engine.In this paper, the elastic-plastic element analysis of high-pressure turbine blades will be made to predict the life of aero engine under the background of needing to predict a turbofan engine life. It is divided into four parts.Firstly, this paper analyzes the stress-strain of turbine blade three-dimensional elastic-plastic element. ANSYS Workbench software is employed to construct a three-dimensional finite element modal of turbine blade for a three dimension cyclic stress-strain analysis. Then, the dangerous positions and points are found, and check the static strength of turbine blades.Secondly, the prediction of low cycle fatigue life and damage analysis will be made. Local stress-strain method is chosen to calculate the life and damage of turbine blade depend on the stress-strain analysis results and material’s fatigue characteristics from three life prediction methods. We select Manson-Coffin formula to build the stress-strain curve.Thirdly, the prediction of creep life and damage analysis will be made. In accordance with the present research situation of creep life and the analysis of load data of turbine blade, the rupture life equation will be used to predict the creep life of turbine blade. We choose the most practical equation to calculate the creep life.Finally, the analysis of fatigue-creep interaction life will be made. On the basis of results of low cycle fatigue life and creep life, the total damage of engine is calculated at last.Depend on the analysis of engine load, this paper makes an analysis of stress-strain, and predicts the life of high-pressure turbine blade. The research methods and results provide a reference to predicting the life and improving the reliability of the turbine blades.