Equivalent method for predicting thermo-mechanical fatigue life

Abstract

The invention provides an equivalent method for predicting the thermo-mechanical fatigue life and relates to the field of fatigue strength. The method comprises the following steps: 1, using a finite element method for calculating out high temperature fatigue data of thermo-mechanical fatigue at the highest temperature and corresponding thermal strain data within a corresponding temperature range; 2, converting an original three-parameter power function energy method at the constant temperature into a three-parameter power function energy method containing thermal strain items by taking thermal strain into consideration; 3, comparing equivalent energy obtained by applying the improved three-parameter power function energy method to data obtained through finite element calculation with energy obtained by calculating data obtained through thermo-mechanical tests; 4, utilizing the improved three-parameter power function energy method for conducting prediction on the thermo-mechanical fatigue life; 5, in engineering, applying a dispersion band and standard deviation to the equivalent energy method and a stretching lagging energy model for measuring the capability of the model for predicting the life. A prediction result shows that the equivalent method can be used for better calculating the thermo-mechanical fatigue life.

Description

technical field [0001] The invention relates to the field of fatigue strength, in particular to an equivalent method for predicting thermomechanical fatigue life. Background technique [0002] Thermal engine fatigue strength design is an important content in the strength design of high-temperature components such as aero-engines and gas turbines. When the engine in actual service is started, steady-state flight and shutdown, the turbine blades of the engine not only bear the constant temperature load but also bear the influence of the thermal load. This loading condition greatly shortens the life of turbine engine blades and reduces the reliability of critical engine components. [0003] At present, the life prediction of thermomechanical fatigue is mainly evaluated by isothermal fatigue under high temperature conditions, but in this case, the damage to the engine caused by temperature changes is ignored, so this traditional method of predicting thermomechanical fatigue by ...

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Problems solved by technology

[0003] At present, the life prediction of thermomechanical fatigue is mainly evaluated by isothermal fatigue under high temperature conditions, but in this case, the damage to the engine caused by temperature changes is ignored, so this traditional method of predicting thermomechanical fatigue by high temperature fatigue Uncertainty about reliability

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