Characterization method of fatigue, creep and fatigue-creep interaction unified life of materials

Abstract

The invention discloses a characterization method of material fatigue, creep, and fatigue-creep interaction service life, and belongs to the field of service life prediction of aero-engine critical materials. The characterization method is used for solving service life characterization and prediction problems of materials under low cycle fatigue, creep, and fatigue-creep interaction conditions. According to the principles, a power function form service life prediction method non-linear behavior characterization capacity is established via fatigue-creep interaction, low cycle fatigue, and creeptests of materials at different holding time, and obtaining of effective holding time and normalization dimensionless service life via normalization calculation method. The characterization method iscapable of realizing accurate characterization of service life of materials under low cycle fatigue and fatigue-creep interaction conditions, and especially, consideration and accurate prediction ofcreep service life can be realized. The advantages of the characterization method are that consideration of both physical mechanisms and model implementation convenience is realized, and material lowcycle fatigue, creep, and fatigue-creep interaction service life characterization and prediction problems are solved effectively.

Description

technical field [0001] The invention is a characterization method for the fatigue, creep and fatigue-creep interactive unified life of a material. [0002] The invention relates to life prediction of aero-engine structural materials and belongs to the technical field of measurement and testing. Background technique [0003] In important national industrial fields such as energy and power, petrochemical, nuclear power and aerospace, many high-temperature structural materials with excellent comprehensive mechanical properties are widely used in the processing and manufacturing of high-temperature components in key parts of industrial products. During service, these high-temperature components often suffer from fatigue damage due to repeated start-stop transient load cycles, and some high-temperature components have to work at a certain stable temperature for a long time, resulting in time-related creep damage , and even some high-temperature components have to work under fati...

AI Technical Summary

Problems solved by technology

Some life prediction models have a certain physical mechanism and have formed a relatively mature theoretical system, but their equations are complex, with many material parameters or even values ​​across scales. The parameter optimization and fitting procedures are cumbersome, and it is not easy to obtain suitable material parameters. As a result, the prediction accuracy will be greatly reduced, and it is not suitable for engineering applications

In addition, some life prediction models are based on the macroscopic phenomenological method, the equation form is simple and the material parameters are easy to obtain, but they lack clear physical meaning, and the basic theory supporting the method research is not perfect, so it is difficult to popularize and apply

So far, researchers at home and abroad have not proposed a reliable, concise and physically meaningful life prediction method that can simultaneously characterize and predict the low-cycle fatigue, creep and fatigue-creep interaction life of materials.

Images