Thermal-Dynamic Coupled Fatigue Reliability Analysis Of Aero-engine Turbine Blades

As the core of aircraft,aero-engine is known as the “flower of industry”,and it is a significant manifestation of national science and technology,industry and national defense capabilities.The environmental temperature and rotation speed of aero-engine are higher than other power systems in the same field.In order to ensure the safety and stability of aero-engine in service,it is necessary to study fatigue reliability.As the important part of aero-engine,aero-engine turbine blades are in complex environment and various loads,which make it easier fatigue failure.Therefore,it is the initial condition to carry out the thermal-dynamic coupling problem and fatigue reliability analysis of aero-engine to in order to ensure normal operation of aero-engine in service.This paper analyzed muti-physics coupling and various loads analysis,and then applied the theory of fatigue reliability to analyze fatigue life of aero-engine turbine blade under specific conditions.First,according to complex working environment and various loads,we described the theory of thermal-dynamic coupling problem and fatigue reliability of aero-engine turbine blades.And applied Fortran,finite element method and finite difference method to write program to calculate to muti-physics coupling and different loads,And classical examples are used to verify that the methods we adopted are correct.Lay the foundation for the following study thermal-dynamic coupling response of aero-engine turbine blades.Second,we got different responses through different loads condition of aero-engine turbine blades: under temperature load only;under aerodynamic load only;under temperature load,aerodynamic load and centrifugal force load.We got the position of dangerous points and its curve of stress-strain under different loads condition of aero-engine turbine blades,At the same time,we chose any two loads from temperature load?aerodynamic load and centrifugal load to calculate,and compared the results.It is pointed that the position of the dangerous will change under different load combinations.Finally,on the basis of the responses we obtained from aero-engine turbine blades under multiple loads.We applied probability fatigue cumulative damage theory,at the same time,considered internal dispersivity of material and external dispersivity of load,combined rain flow counting method?Goodman linear model.The fatigue reliability probability of the aero-engine turbine blades is given.Meanwhile,the duration of the reliability of aero-engine turbine blade is given under the reliability probability 50%.