A damage mechanics approach for lifetime estimation of wind turbine gearbox materials

Wind turbine gearboxes (WTG) have been suffering from premature failures and rarely live up to their designed lifetime. This study focuses on a better understanding of WTG failures. A finite element model of a gear pair was coupled with a constitutive model to quantify and predict damage, while also testing for different service conditions. A damage mechanics formulation is presented based on a physics-based dislocation slip model. Additionally, an estimation of the remaining useful lifetime of the component was generated, further assisting wind turbine farm operators to move towards the implementation of a truly predictive maintenance approach.