Damage Identification of Structures Based on Smooth Orthogonal Decomposition and Improved Beetle Antennae Search Algorithm

Table 4

Element stiffness reduction ratio.

Damage case	Noise level	Damaged element number	Preset value (%)	Calculated value (%)	Error (%)
Single damage	Without noise	10	30	29.89	0.37
	0.2%	10	30	30.11	0.37
	0.5%	10	30	29.87	0.43
Double damage	Without noise	8	30	30.35	1.17
		18	30	29.95	0.17
	0.2%	8	30	30.55	1.83
		18	30	30.64	2.13
	0.5%	8	30	31.32	4.40
		18	30	31.43	4.77