Research progress on notch effect of high temperature components under creep-fatigue loading

With the energy shortage problem more and more serious, the research and development of the high-end equipment (high temperature, high pressure, etc.) is an important measure for energy saving and loss reducing, such as the ultra supercritical steam turbine, aircraft engine and so on. In practical engineering, the failure of much equipment, including the ultra-supercritical steam turbine and aircraft engine, usually originates from notch and some other local structural discontinuities. Its strength analysis and design under complex loadings, such as creep-fatigue loadings, are the main research emphasis and difficulties. In this work, several aspects of notched components subjected to creep-fatigue loading are reviewed, including experimental studies, constitutive equations, life prediction models, numerical analyses and design criteria. Main research progresses are as follows: Some new constitutive models under creep-fatigue loading and their applications, new models and methods for high temperature strength and life analyses, study on simplified model test (SMT) approach and strength criteria of high temperature components under creep-fatigue loading. Current problems and research prospects in future are summarized. The work can provide some technical support and references for strength analysis and design of the high-end equipment under creep-fatigue and other complicated loadings. © 2015 Journal of Mechanical Engineering.