频闪全息测振的误差分析

本文讨论了频闪全息干涉测振技术在进行模态分析时,由于采用激振频率离散步进的方式进行激励,在共振区往往会产生峰值测量误差,提出如何根据最大允许测试误差选择合适的离散频率增量;文中还探讨了文献[1]中所提出的复模态分析方法,由于被测系统有一定的非线性而产生的理论误差,和当激励信号本身存在一定的失真度时,由于高阶次谐波分量与系统的高阶共振频率一致而引起的系统共振响应对测试结果的影响;指出了影响测试结果最严重的是较低阶次非谐振分量.

ANALYSIS OF VIBRATION MEASUREMENT ACCURACY WITH STROBOSCOPIC HOLOGRAPHY

In modal analysis by the use of stroboscopic holographic,interferometry,the dispersion-stepped exciting method must be used.This paper deals with the measurement error of resonant vibration peak because of the dispersed excitation frequency.On the basis of maximum allowing measurement error,the approach to the selection of the suitable dispersed frequency increment is presented,Another question is probed that the analysis method which is given in the reference [1] is used in the dual modal analysis,the theoretical error would be caused because of the weak nonlinear system,and that when the excitation signgal exists some distortion,the high frequency harmonic signal will cause the system resonant frequency vibration if it is the same with the system resonant frequency,its influence on the measurement results is approached.Finally,the paper points out that the most serious effect on the measurement result is the lower harmonic frequency.