地震随机载荷作用下风力机整体振动非线性特性研究

Study on Nonlinear Characteristics ofWind Turbine Vibration Under Earthquake Random Load

风力机的整体结构属于半刚性结构,且等效质量位于塔顶法兰盘几何中心位置,故导致风力机在抗震特性设计上存在缺陷。同时,在地壳随机激振力的作用下,风轮叶尖及翼型后缘位置易产生“鞭梢效应”,放大其激振力响应效果,降低风力机运行安全性。通过计算随机风载荷及地震激振载荷,模拟生成风力机振动加速度的时间历程,提取耦合作用的载荷谱文件,并施加于风力机本体的数学模型上。利用对风力机整体结构的模态分析和响应谱分析,得到风力机在风载荷及地震随机载荷耦合作用下的振动响应,为提高风力机抗震特性和运行安全性分析提供一定的参考依据,并为进一步优化风力机结构设计提供一种工程方法。

The whole structure of wind turbine belongs to semi-rigid structure and the equivalent mass is located in the geometric center of the tower top flange,so there are defects in the wind turbine design of seismic characteristics.At the same time,under the random excitation force of the crust,the blade tip and trailing edge in the airfoil are easier to produce"whipping effect",which amplifies the response effect of the excitation force and reduces the operation safety of wind turbine.In this paper,the vibration acceleration time history of wind turbine is simulated by numerical calculation of random wind load and seismic excitation load.The load spectrum file of coupling action is extracted and applied to the mathematical model of wind turbine.By Modal and response spectrum analysis on the whole structure of wind turbine,it is obtained that the vibration response of wind turbine under coupling action of wind load and seismic random load.The research in this paper can provide some reference for improving the seismic characteristics and operation safety analysis of wind turbines,and provide an engineering method for further optimizing the structure design of wind turbines too.