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

Table 4

Comparison of modal frequencies between refined and equivalent models.

Mode order	Experimental (Hz)	Numerical
		Refined model (Hz)	Error (%)	Equivalent model (Hz)	Error (%)	Diff. (%)
1	189.90	213.17	12.25	213.32	12.33	−0.02
2	204.59	125.05	−38.88	125.37	−38.72	0.26
3	387.64	414.38	6.90	415.23	7.12	0.21
4	439.56	322.22	−26.69	324.71	−26.13	0.77
5	583.81	609.20	4.35	610.97	4.65	0.29
6	672.74	578.64	−13.99	561.10	−16.59	−3.03

Error = (f^r − f^e)/f^e × 100%; Error = (f^eq − f^e)/f^e × 100%; Diff. = (f^eq − f^r)/f^r × 100%; f^r is the analytical frequency of the refined model; f^eq is the analytical frequency of the equivalent model; f^e is the experimental frequency.