Research On Life Predition Methods For High Temperature Components In Short Life Turbine Engine

Small short life turbine engine is the powerplant of cruise missiles and some other unmanned airvehicles. For the expendable usage, low cost is an important design requirement for this type engines.In addition to the requirements of low cost, high reliability is another important design requirementfor these engines. The engine structures need to have enough strength and life. It’s of engineeringsignificance to carry out research on the strength and life prediction methods for the short life enginestructures.Focus on the need of strength design analysis of short-life turbine engine high temperaturestructures, research is carried out on the endurance life prediction methods for the short life TC11titanium alloy engine structures in this thesis. The main research result is as follows:High temperature tension and creep/endurance tests are carried out for TC11titanium alloy. Thetension stress-strain curves, creep curves and endurance life data in the range of11to110hours at500℃are obtained. The endurance tests are carried out for TC11notch samples. The endurance lifedata for three type notches is obtained.The constitutive equations for describing TC11engineering stress-strain curves and truestress-strain curves are founded based on the nonlinear isotropic hardening models. The result showsthat this model can describe the stress-strain curves well. The creep constitutive equations fordescribing TC11engineering stress creep curves and true stress creep curves are founded based on theθ projection method. The result shows that the θ projection method can describe all the threestages of TC11creep curves.Three endurance life prediction methods based on small deformation finite element analysis areevaluated. The result shows that the method based on the area average von Mises equivalent stressand endurance life equations can predict the endurance life of notch well. The life prediction result iswithin the scatter band of2of the test result.A method based on large deformation finite element analysis for endurance life prediction isproposed. The feasibility of the method is evaluated by the TC11notch endurance test data. The resultshows that the life prediction result is good. The prediction result is within the scatter band of2of thetest result.