Failure Hypotheses I
Failure hypotheses for predicting the fatigue life of composite plain bearings
Result
The project identified the quadratic failure hypothesis as the appropriate hypothesis to assess local loading with respect to the material fatigue strength of white metals as a sliding layer material. Calculation of the load factor included aspects such as thermal expansion and installation stresses and demonstrated the importance of a comprehensive depiction of load factors.
Motivation
Plain bearings are used as machine elements in many engines and turbo-machines in a wide range of applications. The continuing trend of cost reduction and increase in power density means that the demands on plain bearings with respect to tolerable surface pressure and maximum dynamic load will only increase. It is therefore necessary to operate sliding layer materials to their strength limit. This requires a reliable forecast of maximum tolerable component loading.
Research objectives
The objective is to create a methodology for interpreting fatigue strength in hydrodynamic bearings. This must include identification of a suitable failure hypothesis for the material and load case, which evaluates loading of the bearing in conformity with experimental investigations.
- Calculation of the material loading under real boundary conditions, such as thermal expansion and installation stresses
- Determination of the component fatigue strength in radial bearings
- Prediction of theoretical component fatigue strength
- Identification of a more suitable failure hypothesis for interpreting fatigue strength in hydrodynamic bearings with a white metal sliding layer
Research and project partners
- Institute for Material Applications in Mechanical Engineering at RWTH Aachen University (IWM)
Promoted by
The German Research Foundation (DFG)
The Research Association for Combustion Engines