风轮固有频率随材质参数变化的规律研究

Research on the law of natural frequencies of wind turbine with different material parameters

风轮的固有频率是风电叶片结构安全性设计中的关键参数。然而由于叶片典型的非线性结构特征,导致材质参数对风轮固有频率影响规律的诠释至今仍不够完备。基于这一背景,该文以小型水平轴风电叶片为研究对象,采用数值计算为主、实验测试为佐证的研究方法,深入探究叶片的固有振动频率随密度、弹性模量和泊松比变化的响应规律。研究发现:风轮1、3阶振型和2阶对称振型的固有频率值随着密度的变化呈现十分明显的二次方曲线规律,2阶反对称振型则呈比较理想的线性规律;风轮1阶、2阶振型固有频率值随弹性模量的变化亦呈十分明显的二次方曲线规律,3阶振型固有频率变化则表现出十分明显的线性特征。相关研究成果对于叶片结构性能的设计与优化具有较有益的参与价值。

The natural frequency of the wind turbine is a key parameter in the safety design of the wind turbine blade structure.However,due to the typical nonlinear structural characteristics of blades,the interpretation of the influence of material parameters on the natural frequency is still lacking.Therefore,this study took small horizontal axis wind turbine blades as the research object,used numerical calculations as the main research method and experimental tests as supporting research methods.Explored the laws of natural vibration frequency of the blades with changes in density,elastic modulus and Poisson’s ratio.It is found that the natural frequency values of the 1st-,3rd-order modes and 2nd-order symmetrical mode of the wind wheel showed obvious quadratic curves with the change of density,and the 2nd-order anti-symmetrical mode showed an ideal linear law.The natural frequency values of the 1st-and 2nd-modes also exhibited quadratic curves with the change of the elastic modulus,and the natural frequency values of the 3rd-mode exhibited a linear characteristic.Relevant research results have beneficial value for the design and optimization of blade structure performance.