Finite element simulation of subsurface initiated damage from non-metallic inclusions in wind turbine gearbox bearings

The premature failure of wind turbine gearbox bearings significantly affects the reliability of wind turbine operation and energy production. Damage initiated from non-metallic inclusions known as White Etching Cracks (WECs) has been identified as the dominant initiation mechanism that causes the premature failure under the influence of transient events. In this study, the factors affecting the initiation of subsurface damage from non-metallic inclusions were investigated by finite element modelling. It was found that the direction of surface traction and loading-unloading cycle had a detrimental effect on stress concentration at the tips of the de-bonded non-metallic inclusions in bearing steel.