极端海况下风力机冲刷效应动力学响应研究

Study on Dynamic Response of Wind Turbine Scour Effect Under Extreme Sea Conditions

基于有限元方法建立考虑土-构耦合效应的壳单元模型,对不同海况下发生冲刷时的海上风力机进行动力学响应分析。结果表明:在常规和极端海况下,发生较大冲刷时,塔顶和桩基顶部峰值位移均有所增加,且桩基顶部峰值位移增幅更大,随着冲刷深度的增加,塔架水平位移均呈先增大后减小的趋势,桩基水平位移随冲刷深度的增加持续增大,不同冲刷深度下桩基最大加速度位置均发生在桩基顶部,塔架最大应力均出现在塔架底部;与常规海况相比,极端海况下风力机在启动后一直处于不稳定状态,最大加速度位于桩基中上部位置,且随冲刷深度的增加持续增大,桩基应力峰值位置由桩基顶部转移至中部。

A shell element model considering soil-structure coupling effect was established to analyze the dynamic response of offshore wind turbine scour effect under different sea conditions based on finite element method.Results show that the peak displacement of the tower top and the top of the pile foundation increase under normal and extreme sea conditions when large scour occurs,and the peak displacement of the top of the pile foundation increases more.With the increase of scour depth,the horizontal displacement of the tower increases first and then decreases.The horizontal displacement of the pile foundation continues to increase with the increase of scour depth.The maximum acceleration position of the pile foundation occurs at the top of the pile foundation for different scour depths,and the maximum stress value of the tower occurs at the bottom of the tower.Compared with conventional sea conditions,the wind turbine in extreme sea conditions has been in unstable state after startup.The maximum acceleration is located in the middle and upper part of the pile foundation and continues to increase with the increase of scour depth.The peak stress of the pile foundation is transferred from the top of the pile foundation to the middle part.