大型风力机叶片的随机振动分析

Random Vibration Analysis of Large-scale Wind Turbine Blade

在不具备风场环境或风洞试验的条件下,基于有限元法建立大型风力机叶片的结构模型和随机风荷载作用下的模拟系统,研究了结构的固有频率和固有振型,以及在给定等效加速度功率谱密度条件下叶片的振动响应随频率的变化规律。通过计算对比发现,叶片结构模型合理有效,可用于模拟实验。在给定加速度功率谱密度条件下,叶尖位移在结构所容许的范围之内;速度和加速度值较小,叶根处最大应力远小于材料的极限应力,结构安全。研究通过对风力机叶片进行随机模拟实验,可以给风力机叶片的制造提供有效的理论依据和安全经济的结构形式。

Without the wind field environment or wind tunnel test,the structural model of large-scale wind turbine blade and the analog system under random wind load are established on the basis of finite element method,and the inherent frequency and vibration mode of structure are researched as well as the change pattern of blade’s vibration response with the frequency under the given equivalent acceleration power spectrum density condition.It is found that the blade’s structural model is reasonable and effective through calculation and contrast,and could be used for the simulation experiment.The blade tip displacement is within the allowable scope of structure when the acceleration power spectrum density is given.The value of speed and acceleration is smaller.The maximum stress on the blade root shall be much less than the limiting stress of materials,with safe structure.The effective theory basis and the safe & economic structural form are provided for manufacturing the wind turbine blade through the random simulation experiment of wind turbine blade.