Model Updating of a Stitched Sandwich Panel Based on Multistage Parameter Selection

Table 6

Comparison of updated modal frequencies between experiment and analysis with different weighting matrices.

Mode order	Experiment (Hz)	Case I: W		Case II: Ẃ
		Numerical (Hz)	Error (%)	Numerical (Hz)	Error (%)
1	189.90	190.66	0.40	190.78	0.46
2	204.59	201.94	−1.29	199.57	−2.46
3	387.64	383.47	−1.08	384.03	−0.93
4	439.56	450.75	2.55	449.97	2.37
5	583.81	593.42	1.65	595.61	2.02
6	672.74	664.87	−1.17	661.87	−1.62
7	751.18	769.54	2.44	770.28	2.54
8	790.16	817.25	3.43	822.75	4.12
9	878.64	909.26	3.48	913.50	3.97
10	916.01	970.10	5.91	979.15	6.89
Mean error			2.34		2.74

Mean error means absolute average error, mean error = .