Reliability Study On The Fatigue Life Of Turbine Disk Which Fusion Material Information

As the core component of aero engine, turbine disk’s reliability is related to the normal operation of the whole engine. Meanwhile, it is also an important basis for exploring the reliability of the whole engine. This paper is aim at the reliability analysis of small sample fatigue life of a certain aero engine turbine disc study, mainly consists of the following three parts.The first part, including the second chapter and the third chapter, which analyzes low cycle fatigue failure distribution type of GH4133 disk material. First of all, through the cause-effect diagram and primary-secondary diagram analysis:the main failure mode of turbine disk is low cycle fatigue failure. Secondly, using empirical distribution function and average failure rate function, accounting the difference of the same temperature of different strain ratio and the same strain ratio of different temperature, the analysis shows that the optimal failure distribution of GH4133 material is log normal distribution.The second part, is the fourth chapter of this paper. It is explores the function relationship between Parameters of failure distribution function of GH4133 material and various influencing factors. First of all, using maximum likelihood estimation method to estimate, by the log normal distribution, the fatigue failure data of GH4133 materials. Then through the diagram method and variance analysis, studied the relationship between strain, temperature, strain ratio and distributed parameter. Finally, the conclusion is that the mean value is affected only by strain, standard deviation is only affected by temperature, and draw the corresponding function curve.The third part, using the fifth and the sixth chapters to analyze the turbine disk’s reliability. First of all, based on the local stress-strain method and combined with the modified Neuber formula, used ANSYS finite element method got the dangerous parts of turbine disk stress-strain history. Secondly, based on Bayesian analysis method, studied of low cycle fatigue life reliability of turbine disk. Analysis shows that the turbine disk low cycle fatigue life expectancy is 3453 cycles, equivalent to 1264 flight hours at this time the reliability of P =50%;When the reliability of P=99.87%, Reliable life of turbine disk t0.9987 is 1668 times, equivalent to 611 flight hours.