Dynamics Response of Wind Turbine Towers under Seismic and Multi Wind Conditions

In order to estimate the dynamics responses of large-scale wind turbines under the conditions of unsteady turbulent winds coupled with different degree of, NREL 5 MW prototype wind turbine was selected as the research object. Soil-structure interaction was taken in account based on Wolf theory, while aerodynamic forces were calculated via generalized dynamic wake and blade element momentum corrected by Prandtl theory. Based on the data interface of FAST, the seismic load computation module was compiled, while the coupling simulation model for turbulent winds and earthquakes was established. The wind turbine tower dynamics response under 150 working conditions including 5 wind speeds and 30 seismic accelerations was calculated. The results show that the tower top displacement is affected significantly by earthquakes under rated wind speeds. Under low wind speeds, tower acceleration is affected greatly by the earthquake conditions. High speed turbulent winds will exacerbate tower shear forces and bending moment responses. With the combinations of turbulent winds and earthquakes, the critical peak ground acceleration(PGA) of tower top displacement, tower top shear forces, tower base shear forces and tower base bending moments increase first and then decrease with the increasing of wind speeds. When wind speeds are high, the critical PGA of tower top acceleration increases with the increasing of wind speeds. © 2019, China Mechanical Engineering Magazine Office. All right reserved.