风机叶片的动力特性直接影响到风力发电机组整体的动力特性,对旋转叶片动力特性的研究是必要的。叶片在旋转过程中由于重力和离心力的作用,将会产生离心刚化效应,从而改变叶片自身的动力特性。基于空间面的概念,本文应用有限元理论计算了随时间和转速二维坐标变化的叶片节点轴力面和叶片的前三阶自振频率面,同时引入刚化系数的概念,定量地描述了叶片的刚化程度,并给出了频率修正公式,结果分析表明本文采用的方法可以模拟旋转叶片产生离心刚化效应后的动力特性,更准确地反映叶片的实际动力特性。
The dynamic characteristics of wind turbine are directly affected by the dynamic characteristics of blade, so it is necessary to study the dynamic characteristics of rotating blade. The rotational blade with the effects of gravity force and centrifugal force will cause centrifugal effect, and will change the blade' s dynamic characters. Based on the concept of spaeial plane and finite element method, this paper calculates the axial force plane of blade nodes and the first three orders of natural frequency plane with two variable parameters of time and rotational speeds, and the stiffening coefficient is also used to describe the stiffening degree of the blade, and then presents the correction formula of frequency. The result shows that the method used in this paper can simulate the dynamic characters of rotational blade with centrifugal stiffening effect, and reflect the practical dynamic characters of the blade more accurately.