应用模态分析及傅里叶变换的柔性转子无试重动平衡方法

A field balancing method of a flexible rotors based on modal analysis and fourier transformation

针对旋转机械不平衡导致的振动问题,提出一种的柔性转子现场动平衡方法。其通过有限元理论建立转子系统动力学模型,并将系统运动微分方程按模态振型展开,利用FFT及IFFT变换,获取频域下不平衡载荷谱,最终识别转子不平衡状态。仿真和试验结果均表明,该方法仅需在低于临界转速的状态下采集振动响应数据,并且无需停机试重,就能准确识别转子不平衡状态,添加配重后可使转子各阶不平衡振动得到有效抑制。

A field balancing method of a flexible rotor was presented to suppress vibration due to imbalance. In this method, a rotor system dynamic model was established with FE theory, and its differential equation of motion was expanded according to its modal shapes. By using FFT and IFFT transformation, the unbalanced load spectrum in frequency domain was acquired, and .then the rotor imbalance was eventually identified. Simulation and experimental results showed that this method can identify the rotor imbalance accurately, it only needs to collect data of vibration response below critical speed without trial weights. After adding counterweights, the imbalance vibration for each mode of the rotor can be effectively suppressed.