Effect Analysis of dynamic water pressure on dynamic response of offshore wind turbine tower

Compared with onshore wind turbine, the offshore wind turbine is more easily destroyed influenced by the complicated conditions at sea. In this study, a refined finite element model of offshore wind turbine in consideration of the soil-structure interaction is built. The dynamic response of the wind turbine tower in different water depths is investigated; then the weak positions of the wind turbine tower under earthquake is determined. We found that the water pressure on one side of the inflow face of pile foundation is the greatest; as the rate of flow increases, the negative water pressure on the contact surface increased more than the positive water pressure. The maximum displacement of the structure influenced by dynamic water pressure is located at the tower top, the maximum equivalent stress strain is located at two-thirds of the tower height, and the maximum bending moment appears at the bottom of the tower. When the water depth increases from 0 m to 5 m, the displacement and bending moment of wind tower structure increased by 29 % and 25 % respectively under the influence of dynamic water pressure; thus the influence of dynamic water pressure on the dynamic response of the structure should be paid attention to. Finally, the shaking table test of the wind turbine is conducted; the test results are compared with the numerical simulation results, and feasibility of the numerical simulation method was verified.