| Wind is a renewable energy which is clean, safe and permanent. Comparing to the land wind power, the offshore wind power has a more abundant resource and a vaster future. Meanwhile, the offshore wind turbine structures face a more complex ocean environment. They suffer kinds of stochastic loads which changes with time and space, such as wind, wave and current and so on. Therefore, the safety and stability of the structures under those loads are the difficulty and emphasis points.. So, it is so important to research the dynamical analysis under main environment loads and the fatigue analysis for the safety and operation in the service period.According to the geological conditions of seabed at the site, the Tripod-Foundation is chosen for the wind farm. The paper mainly emphases on the following contents:1) The main environment loads are calculated. It is used the nonlinear Stokes5wave theory and Morison equation for wave load. Time history curve of wave load is got by changing from P-M wave spectrum. Time history curve of wind load at different elevation is got by filter method.2) Build support structure finite-element model in ANSYS, The dynamical analysis under wave and wind loads was made for the extreme and normal working conditions. We can ensure the main loads from results, then the coupling loads of stochastic mian loads with maximum miner loads are applied to analyze the dynamical responses of support structure for the extreme and normal states. The results show that the responses of structure for the normal state is bigger than that for the extreme state, and the response results mainly present the traits of wind load.3) The method of S-N curve and Linear accumulative damage method are employed to calculate the fatigue damage for the place of stress concentration by hot pot stress method.Fatigue damage under wind fatigue load and wave fatigue load is calculated respectively, and overplayed by damage coupling method, then got the total fatigue damage. |
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