Results show that 27 or 20 principal components can extract the dominating features of FRF, and the corresponding covariances of the reconstruction error are 0.0097 and 0.0134 respectively.

• 误差分析结果表明，采用27或20个主元能提取润扬悬索桥的主要动力特征，重构误差的均方值分别为0.；0097和0