Fatigue life prediction for wind turbine main shaft bearings

Abstract

Taking the wind turbine main shaft bearing as the research object, the actual working status of the main shaft bearing under radial load and axial load is considered. Using the ANSYS software, the contact stress under different working conditions are analyzed, the dangerous position of main shaft bearing and the stress analysis results of dangerous position are determined. Based on the results of stress analysis, the main shaft bearing's S-N curve is obtained by changing the material's S-N curve. Considering the influence of average stress to fatigue damage, the average stress is corrected using the Goodman formula. According to the nominal stress approach and the fatigue damage cumulative rule, the fatigue life of the wind turbine main shaft bearing is predicted under combined action of different working conditions. The prediction result is 24.07 years, which meets with the requirement of 20-year design life of wind turbines.