Research On Aviation Engine Blades Creep Life Based On The Reliability

Aviation engine blade works in the environment that is full of high temperature gas and high pressure gas. It is the most serious parts that suffer force and heat in the engine. There are many forms of blade failure, which is mainly caused by creep deformation or fracture. This paper, which regards blade as the object, has predicted creep life and made a reliability analysis. Main works as follows:(1) The paper, which based on the China aviation material manual test data and the theory of creep lasting life prediction, has established four kinds of prediction model that belong to the time-temperature parameter method. These models are Larson-Miller parameter method (L-M), Ge-Dorn parameter method (G-D), Manson-Succop parameter method (M-S) and Manson-Hafered parameter method (M-H). In addition, the linear least squares are used to get unknown parameter values which are existed in the models. The extrapolation model, which is called hot strong comprehensive parameter model, is also used for predicting lasting life.(2) The paper, which based on China aviation material manual test data and the theory of creep deformation of life prediction, discussed the established methods of two kinds of prediction model such as θ-prediction method and improved θ-prediction method. In addition, the Newton-trust region algorithm is used to calculate unknown parameters in nonlinear regression model. It ensures the convergence of solution and reduces depending on initial value in solving nonlinear iteration. The extrapolation model is also used for predicting lasting life.(3) Due to creep life value is impacted acutely by the material performance of dispersion, therefore, it is necessary for creep life prediction to have reliability analysis.This paper, which based on creep life prediction model, has proposed system solutions of reliability analysis. The methods included abnormal data processing, parameter estimation and test of goodness of fit. Ultimately, it determined the type of the distribute data and calculated long-term creep life value at 95% confidence level and any reliability level.(4) The paper, which based on the theory of linear fatigue cumulative damage, time temperature parameter model and the method of creep life prediction, has analyzed the reliability of material creep damage accumulation(5) The software about creep life prediction and reliability analysis, which is based on MATLAB/GUI platform. Its main features include:reading and saving data, generating graphics of fitting curve and showing the results of predicting and analyzing. It reduces the calculation time of creep life prediction and analysis and improves work efficiency.The software has many trits includes simple interface and convenient operation. In addition to these, it also has strong compatibility and applicable widely. Above all, it can also be used for other material creep life prediction and reliability analysis.