Isomap-Based Three-Dimensional Operational Modal Analysis

Table 17

PCA and Isomap by DMA with a real modal damping ratio of 0.03.

Real order	Identified order	DMA
		PCA (MDS)			Isomap
		MAC	Frequencies	Relative error (%)	MAC	Frequencies	Relative error (%)
1	2	0.6554	1059	0.389	0.6564	1059	0.389
2	1	0.6180	1151	0.463	0.6180	1149	0.288
3	3	0.7833	1237	−0.210	0.7817	1237	−0.210
4	4	0.5284	1443	0.076	0.5241	1441	−0.062
5	6	0.7289	1738	−0.115	0.0049	—	—
7	5	0.9038	1873	0.069	0.8932	1874	0.123