用频响函数曲线拟合法识别壳体模态参数

叶片工作在大气湍流随机变化的恶劣环境中 ,具有曲线边界 ,自振频率的求解是对其进行动态设计的需要 ,大部分叶片在工作中常常先于整机破坏而导致整个设备停止运行。其振动参数的识别对其设计制造具有指导意义。通过对风力机叶片进行动态测试 ,由频率分析的单模态曲线拟合方法及复峰值曲线拟合方法方得到了叶片的前八阶振型曲线图 ,二者结果比较一致 ,并找出了结构的薄弱问题。试验结果表明 ,此叶片一阶频率小于该叶片在额定转速下的三倍转速频率 ,这可能是该叶片容易失效的原因之一 ,对风力机叶片的结构动力修改及结构动态优化设计提出了参考意见 ,为叶片动态设计打下了基础

Identifying Modal Parameters of a Shell Structure by Using the Transfer Function Curve Fitting Method

Blade works in the bad circumstance of atmosphere swift current changing randomly.The solution with curve boundary and free vibration frequency is requirement to dynamic design. Most of the blade often fail before the whole equipment fail ,and make the whole system out of work. Identifying vibration parameters can guild it's design and manufacture. Through the dynamic testing to horizontal axis wind turbines, the first 8th frequency and modal shape were obtained by SDOF and MDOF of the frequency analysis, both have the close results,and vulnerable place in structure had been located. The test result shows that it's first modal frequency is three times lower than the rotating speed. This may be one of the reasons causing the blade failure. The reference opinion for modifying and optimizing the design of dynamicstructure of blade in wind turbines was put foreword. This lays the foundation of the dynamic design of the turbines.