对超高速摄影仪转镜动力学特性提出了系统的数值分析方法,包括对转镜分别进行模态、谐响应、灵敏度数值分析和试验研究.首先利用数值方法提取出转镜前5阶固有频率、振型及转镜幅频特性曲线,发现转镜的1阶和2阶共振带出现了叠加现象,在1阶弯曲振动处幅频特性曲线上的峰值远大于其它各阶的峰值,最大应力出现在转轴上,说明转轴的损伤是转镜失效的主要形式,1阶弯曲是转镜失效的主要原因.为验证转镜结构尺寸与转镜固有频率的关系,利用ANSYS参量化设计语言建立转镜固有频率灵敏度分析模型,使用ANSYS概率设计模块对转镜进行了固有频率灵敏度数值分析.计算结果表明,镜体外接圆半径和转轴轴段2半径对转镜固有频率影响最大.灵敏度实验结果表明,转镜的结构尺寸改变引起的转镜固有频率的改变方式和改变程度与数值分析结果是一致的.为转镜动力学设计提供了较高准确度的数值分析方法.

A model and harmonic simulation analysis and experiments have been done separately by the finite element analysis software ANSYS and its first five natural frequencies,vibration models and the frequency response curve of rotating mirror were obtained.In the displacement frequency response curve of rotating mirror,the resonance bands of torsional vibration and bending vibration were overlapped,and the maximum peak value at the first bending vibration was greater than others.The stress of the first bending vibration was much larger than the others and the maximum stress appeared in the shaft.The main form of failure is the damage of the shaft,and the front bending vibration is the main reason of rotating mirror failure.With the model of rotating mirror natural frequency sensitivity compiled by ANSYS Parametric Design Language ,the numerical analysis and experiment of rotating mirror natural frequency have been done using the Probabilistic Design System of ANSYS to study the interrelationship between physical dimensions and the natural frequencies.The numerical results reveal that the dependency of the circumcircle radius R5 of mirror body and the radius of shaft 2 with the same frequency is opposite,and the degree of correlation of R5 and R2 is higher than anther.The results of experiment show that the change mode and degree due to the same change of different structural parameters of rotating mirror is identical with numerical analysis.This study provides a quantifiable indicator for dynamic design of rotating mirror.