基于摄动模态分析的风电叶片动力学特性研究

RESEARCH ON DYNAMIC CHARACTERISTICS OF WIND POWER BLADES BASED ON PERTURBATION MODE ANALYSIS

针对大尺寸叶片运行状态下受旋转软化效应和动力刚化效应耦合作用从而导致其模态特性改变的现象,提出一种基于摄动模态分析的旋转叶片振动分析方法。建立0.89 m和61.5 m两种型号的叶片模型,通过数值模拟分析叶片在0~50 r/min转速范围内这两种效应对叶片频率的影响。基于计算的频率差值Δf的变化规律,研究叶片3种主要振型与这两种效应之间的关联关系。最后,为验证数值模拟的准确性,通过锤击法进行实验模态分析并与数值模拟结果进行比较。实验结果表明,其一、二阶模态频率误差均在1%以内,计算结果较为准确。

In view of the phenomenon that the blade is coupled by rotating softening effect and dynamic stiffening effect,which leads to the change of its modal characteristics under the operating state of large-scale blade,a vibration analysis method of rotating blade based on perturbation modal analysis is proposed.In this paper,two blade models of 0.89 m and 61.5 m are established.Through numerical simulation,the influence of two effects on blade frequency at 0-50 r/min speed is analyzed.Based on the variation rule of calculated frequency differenceΔf,the correlation between the three main modes of blade and the two effects is studied.Finally,in order to verify the accuracy of numerical simulation,experimental modal analysis and numerical simulation results are compared by hammering method.The experimental results show that the errors of first and second order mode frequencies are within 1%,and the calculation results in this paper are more accurate.