Fatigue analysis on contact interface of aero-engine bearing based on stress analysis

For aero-engine main shaft bearings, fatigue damage is one of the main failure models in the contact interface of rolling elements and raceways. In this paper, the fatigue damage of the bearing is analyzed based on the stress. The feature changing rules of the quasi-static alternating stress and the dynamics contact stress are obtained respectively in the quasi-static and the dynamic method. Based on the stress of bearing, we can analyze the formation mechanism of damage, as well as the effectiveness of the different analysis methods. In the normal operation condition, the bearing fatigue is the composite fatigue of the normal high cycle fatigue and the rolling contact fatigue, owing to the combined action of the principal and max shear stress. Under the large axial load, the normal high cycle fatigue due to the principal stress can be the major fatigue damage mode; while the lager centrifugal load (high rotation rate) will highlight the rolling contact fatigue due to the max shear stress. The quasi-static method and the dynamic method are both suitable for the principal stress analysis, but only the dynamic method can be used to analyze the rolling contact fatigue due to the max shear stress. The dynamic method is more suitable for the comprehensive analysis of bearings.