Analysing Crack Evolution in Wind Turbine Bearings Using an Oscillation-Unified Model

In wind turbine bearings subjected to oscillating motion, cracks undergoing reciprocating rolling contact loading experience more complex stress changes compared to those under constant rotational motion. However, oscillation is less explored. This study introduces an Oscillation Unified Surface-Initiated Crack Finite Element Model (OU-CFEM) to address this gap. The model is validated through mesh sensitivity analysis and Oscillation Contact Fatigue (OCF) experimental data. The OU-CFEM enables a detailed investigation into crack evolution characteristics under varying initial angles and friction coefficients. The findings reveal that crack behaviors significantly differ across different oscillation phases, except in cases involving vertically oriented cracks or fully lubricated conditions. The study highlights that larger initial angles and higher friction coefficients promote crack extension, with the initial angle playing a more critical role in crack evolution than the friction coefficient. This research provides new insights into the behavior of cracks in oscillating conditions, offering valuable contributions to the understanding of wind turbine bearing durability under such loading scenarios.