Wind Vortex-induced Vibration And Fatigue Analysis Of Offshore Wind Power Structure

Wind is a green energy resource. Wind power is the world's fastest growing energy technology, our country is developing a offshore wind farm.The structural of offshore wind turbine principally withstands periodic and random loads. But the random loads mainly come from the wind load. Nature of the wind in time and space with more variability, making the wind on the structural of offshore wind tower is very complex. In time, wind speed fluctuation and frequent shedding of vortices wind will cause the vibration of the tower structure. Therefore, the research has a certain significance.Based on the RANS method and SST turbulence model, combined with the dynamic mesh, bi-directional flow using ANSYS+CFX fluid-structure coupling methods for offshore wind tower wind vortex-induced vibration simulation. We obtain the role of vortex-induced vibration in the wind stress at the time under the hot spot location. Using the linear filtering method, based on autoregressive (AR) model, we make Matlab program to simulate the tower at different heights fluctuating wind load time history. We obtain the fluctuating wind loads in the tower when the hot spot stress at the curves. Both the stress conditions at the tower under the hot location process rain-flow count, namely the preparation of the tower of variable amplitude loading spectrum, combined with DNV to provide the S-N curve and Miner linear cumulative damage theory. Respectively, the offshore wind power tower was estimated fatigue life, and compared.Aiming at the study of fatigue life assessment of offshore wind power structure under the wind vortex-induced vibration.We established the fatigue life calculation system of offshore wind power structure in this thesis. We provided for the design of offshore wind power tower a reasonable theoretical on the optimal design of future reference. To our development of offshore wind power industry, it has some practical values.