Reliability Analysis Of Turbine Blisk With Fatigue-Creep Coupling Failure

As the key component of aero-engine,the blisk will subject to complex loads,such as the high temperature,high pressure and high speed,and its reliability is very important to the safe flight of aircraft.In order to improve the accuracy of reliability analysis,the intelligent response surface agent model which is by means of Response Surface method(RSM)and Extreme Response Surface Method(ERSM),combining genetic algorithm and kriging model to analyze the fatigue and creep coupling failure reliability of turbine blisk.These include:(1)Reliability analysis of high temperature creep failure of turbine blisk structure.Firstly,the creep properties of GH4133 B were obtained by statistical analysis of data that obtained from the creep tensile test at high temperature.Then Dual Response Surface Method(DRSM)is applied to the reliability analysis of creep failure at high temperature.Kriging Dual Response Surface Method(KDRSM)is combining kriging model and response surface.The kriging model was trained by taking the temperature,rotation,speed,material,rotation speed,material density and modulus of elasticity as the input variables and stress and strain of the disk creep as the output response.The KDRSM model was constructed to analysis the creep reliability of the turbine blisk at high temperature.Finally,the two methods are compared to verify the effectiveness of the new method.(2)Reliability analysis of low cycle failure of turbine blisk structure.The low cycle fatigue performance parameter of GH4133 B were obtained by fatigue test data.The Extreme Response Surface Based on Genetic and kriging Algorithm(GK-ERSM)is proposed by combining genetic algorithm and kriging model.Latin Hypercube sampling technique is used to extract input random variable samples and the dynamic extremum response in time domain of [0,T],genetic algorithm is used to search the optimal correlation parameters of kriging model in the maximum likelihood estimation,and established the GK-ERSM mathematical model.The reliability and sensitivity of low cycle fatigue life of aero-engine integral turbine blisk structure are analyzed and studied.(3)Fatigue and creep coupled failure reliability analysis of turbine blisk.Firstly,the fatigue creep coupling test data under trapezoid wave are processed and the fatigue creep coupling characteristic function is fitted.Then Multicomponent Coupling Failure Reliability Analysis based on genetic and kriging algorithm(GK-MERSM)is proposed.The maximum stress point and the maximum deformation point of the blade-disk structure are obtained by thermostructural coupling deterministic analysis,and deterministic the dangerous position.The fatigue creep coupled damage was solved by using MATLAB to program the damage and life formula,and the output data samples of the extreme value of blade-disk were obtained by using the center group method.The parameters of Kriging model are optimized by genetic algorithm,and the mathematical model of GK-MERSM is established.Finally,the dynamic reliability analysis of this mathematical model is carried out by using Monte Carlo method(MCM),and the sensitivity distribution of the fatigue creep coupling damage of the blade-disk is obtained.