Sensitivity analysis of rolling bearing fatigue life under cyclic loading

Rolling bearings are regularly subjected to cyclic loading, and the load changing sequence has a significant influence on bearing fatigue life. The study offers a cumulative fatigue damage theory based on the improved Lundberg-Palmgren method that takes into account the effect of load changing sequence on bearing fatigue life and then proposes a modified Miner bearing fatigue life model. Additionally, the state function for the bearing fatigue life analysis is developed based on the basic dynamic load rating and stress-strength interference model of the bearing. A moment-based sensitivity analysis method for bearing fatigue life is proposed for studying the influence of different variables on bearing fatigue life. Finally, a sensitivity analysis of the fatigue life of 6209 deep groove ball bearings was performed as an example. The calculation results demonstrate that the modified Miner life model is comprehensive and that the moment-based sensitivity analysis method is simple and accurate.