用随机减量技术及ITD法识别工作模态参数

Operating modal parameter identification by random decrement technique and ibrahim time domain

在许多情况下环境激励是无法测量的 ,假设环境对振动系统的激励是均值为零的白噪声 ,用随机减量技术将系统的自由振动信号从随机响应信号中分离出来 ,然后再用 ITD法识别系统的模态参数。整个过程均在时域内进行 ,避免了时频转换中出现的“谱泄漏”

The embient excitation can't be measured in many cases The embient excitation to the vibration system is considerd as white noise with naught of expectation Free vibration signal of the system is separated from random response signal by random decrement technique And then the modal parameters of the system are identified by ibrahim time domain The total process is done in time domain and so the spectrum leakage is avoided from time domain to frequency domain