Forced Vibration Analysis And Fatigue Life Estimation For Rigid-flexible Coupled Wind Turbine Gearbox

Recently, wind power capacity is increasing stably. However, wind turbine gearboxes’failure rate is high, service life is short and they run unstably. Vibration and fatigue are two important factors for the above problems. Thus, wind turbine gearboxes’vibration and fatigue are studied and the following is main work:First, a parameterized modeling method is adopted to establish three dimensional models for components of the wind turbine gearbox’s transmission chain with PRO/E according to the drawing. Every component is assembled reasonably in order to create the gearbox transmission system model, which is imported to ADAMS to generate the rigid model. Then, ring gears, planet gears, the planet carrier and the high speed shaft are flexible via ANSYS and corresponding rigid body parts are replaced with them to establish the rigid-flexible coupled model.Second, constraints are added to the mode. Additionally, input speed excitation and torque excitation are applied to the planet carrier’s interface node and the high speed shaft’s respectively. The system’s vibration characteristic and feasibility are analyzed from system modes, modal participation factors and frequency response. Third, dynamic simulations for constant loads and fluctuating loads are conducted. Simulation results of transmission rate, contact force, contact stress and bending stress are coincident to identify the model’s validity. Two cases’top ten hot spots’ stress and strain are extracted and it is pointed out that speed impact and torque impact cause great damage to wind turbine gearboxes.In the end, its fatigue life is estimated with the rain flow count method, material’s P-S-N curves and the Miner rule, according to the critical components’ simulation stress for two cases. The results indicate that the design can meet the requirements.