A High-Temperature Sliding Contact Fatigue Life Prediction Model Based on Surface Integrity

Abstract

Fatigue failure of mechanical components at high temperatures and in the presence of sliding contact is a serious problem in the field of aero-engine and advanced gas turbine main equipment. Traditional life prediction models generally assume that the material is a homogeneous body and do not fully consider the significant influence of the surface integrity state, which is determined by the joint effect of manufacturing and service, on fatigue behaviour; thus, there is a large spread in the prediction results. Therefore, the aim of this paper is to construct a physics-mechanism-based life prediction model that can take into account all kinds of attributes of surface damage. The above are the ways to determine the shape of the surface, residual stress and microstructure, as well as the change laws of these under high-temperature sliding contact. It has been shown that many kinds of damage occur in thermo-mechanical coupling and creep-fatigue interaction. According to the theory of multi-scale damage coupling, this paper proposes a general system to quantify all kinds of parameters in the damage evolution equation related to the surface condition and develops a numerical solution algorithm that combines the finite element method with damage mechanics. The model can simulate all the changes in the bad surface condition and the final failure, so it is a very good theoretical tool for studying anti-fatigue design and the reliability of high-temperature sliding contact parts.