Abstract
Keywords: thermo-mechanical fatigue, engine, Sehitoglu
Nowadays engine components are subjected to higher loads at elevated temperatures than before, due to the increasing requirements regarding weight, performance and exhaust gas emission. Thus, fatigue due to simultaneous thermal and mechanical loading became determinant among the damage forms.
At the same time, there is the need to reduce development times and costs to handle the growing number of model variants. Therefore, the development of suitable simulation tools, which reduce the number of necessary component tests, seems to be very rewarding.
The problem of thermo-mechanical fatigue (TMF) life prediction has received considerable attention in recent years, with efforts principally concentrated on the prediction of TMF under uniformly repeated loading conditions. Several researchers have developed models to treat this problem, generally based on isothermal (IT) considerations. However, isothermal tests do not capture all damage mechanisms that operate under variable strain-temperature conditions. As Sehitoglu emphasizes, a deeper understanding of the different micro mechanisms affecting the behavior of materials under isothermal and thermo-mechanical loading conditions is needed.