Numerical and Experimental Investigation on Parameter Identification of Time-Varying Dynamical System Using Hilbert Transform and Empirical Mode Decomposition

Table 2

Identification error of frequency and damping ratio at different time instant (SDOF Example 2).

Time instant (sec.)	Natural frequency (Hz)			Damping ratio (%)
	Theory	Identify	Error (%)	Theory	Identify	Error (%)
2	4.044	4.057	0.31	0.0618	0.0601	2.81
4	3.761	3.79	0.74	0.0447	0.0358	19.8
6	5.623	5.477	2.68	0.0348	0.0471	35.2
8	4.486	4.547	1.37	0.0595	0.0562	5.57
10	3.572	3.573	0.024	0.0524	0.0482	8.08
12	5.627	5.584	0.77	0.0338	0.04	18.3
16	3.444	3.484	1.11	0.0605	0.059	2.51
20	5.294	20	73.5	0.0532	0.05	5.99