一种基于互功率谱密度的频域模态识别法

Modal Parameter Identification Using Cross-Power Spectra Density

对各测点响应的互功率谱密度函数进行了详细推导 ,提出了一种基于互功率谱密度的频域多参点辨识法 ,这意味着许多原本利用频响函数的传统频域识别法可以很容易地用于工作状态下的模态识别 ,大大开阔了未知激励下模态识别的视野。然后采用一飞机模型对该方法进行了试验验证 ,结果表明 ,本文所提出的方法确实可行。

Only response can be used to extract modal parameters under operating conditions. In the situation where it is very difficult to measure excitation. Very few methods are available in frequency domain on this issue. A method of cross-power spectral density between responses is derived and a poly-reference modal analysis method using cross-power spectral density method in frequency domain is presented in this paper. The method developed in this paper makes it easy to extract modal parameters under operating conditions. Then an experiment on an aircraft model is performed in order to verify the proposed method in this paper. The results demonstrate that it is feasible.