Maintaining Specific Natural Frequency of Damped System despite Mass Modification

Table 5

Second frequency and error under different modal damping ratios.

Cases	Modal damping ratio of the second frequency (%)
Methods	0.84	1.66	2.52	3.39	4.24
Real method
Frequency (Hz)	0.1447	0.1440	0.1438	0.1435	0.1397
Error (%)	0.178	0.69	0.82	1.05	3.66
Optimal selection method
Frequency (Hz)	0.1447	0.1440	0.1438	0.1435	0.1397
Error (%)	0.178	0.69	0.82	1.05	3.66
Absolute value method
Frequency (Hz)	0.1449	0.1447	0.1444	0.1441	0.1438
Error (%)	0.06	0.20	0.40	0.62	0.83