Thermal Fatigue Reliability Analysis Of Aeroengine Key Components

The core rotating parts of the aero-engine—turbine blades and turbine discs are under high temperature and pressure,complex loads,environmental corrosion and other harsh conditions in the long-term.Therefore,serious consequences will be brought in the event of fatigue damage.In the paper,based on finite element software ANSYS Workbench and PDS,a numerical study of thermal fatigue reliability was done by setting four temperature gradient conditions(100~300 ?C,300~600 ?C,600~900 ?C,900~1200 ?C)for turbine engine blades and turbine disks.The thermal stress and strain distribution of the components under various temperature conditions were obtained.Fatigue life prediction and Monte Carlo reliability analysis were performed.The simulation results are of great significance to improve the overall reliability and safety of aero-engine.The paper contains three main parts:(1)Three-dimensional models of turbine blade and turbine disk were established by using 3D mapping software Solidworks.Then the finite element models of turbine blade and turbine disk were established by introducing ANSYS software.Using tetrahedral mesh,enter parameters and constraints.The steady state thermal analysis was done by setting four temperature gradient conditions.The temperature field and thermal stress strain distribution of turbine blades and turbine discs were obtained.The dangerous parts,thermal stress strain distributions of turbine blades and turbine discs were determined.(2)The nominal stress method,local stress strain method and fatigue damage accumulation theory are applied to analyze the thermal fatigue of turbine blades and turbine discs.The fatigue sensitivity curves of four groups of turbine blades and turbine disks under temperature conditions were obtained.The fatigue life distribution and fatigue-sensitive area of turbine blade and turbine disk were analyzed.(3)Based on the ANSYS PDS module,the maximum thermal stress of the components under four temperature conditions was taken as a random variable.The reliability analysis of the turbine blades and turbine disks were implemented by Monte Carlo finite element method.The probability distribution and reliability of turbine disk and turbine blade under the action of temperature field were analyzed.