Structural Damage Detection Based on Modal Parameters Using Continuous Ant Colony Optimization

Table 11

Multiple damage detection in space frame structure.

Damage case	Element number	Actual damage	Detected damage			Percentage error
Percentage of noise included*			0	5	10	0	5	10
H1	3	20	20.00	18.67	17.96	0.00	6.65	10.20
H2	18	10	10.00	9.28	11.92	0.00	7.20	19.20
H3	27	15	15.00	14.26	13.22	0.00	4.93	11.87
H4	3	20	20.00	18.41	18.62	0.00	7.95	6.90
	22	30	30.00	28.86	27.50	0.00	3.80	8.33
H5	3	20	20.00	21.56	17.86	0.00	7.80	10.70
	27	15	15.00	14.69	12.84	0.00	2.07	14.40
H6	18	10	10.00	9.50	9.03	0.00	5.00	9.70
	23	25	25.00	23.46	29.53	0.00	6.16	18.12
H7	3	20	20.00	19.80	23.20	0.00	1.00	16.00
	18	10	10.00	8.93	9.34	0.00	10.70	6.60
	27	15	15.00	14.86	17.77	0.00	0.93	18.47
H8	3	20	20.00	18.40	18.50	0.00	8.00	7.50
	22	30	30.00	29.68	26.80	0.00	1.07	10.67
	32	20	20.00	17.94	22.72	0.00	10.30	13.60
H9	18	10	10.00	10.80	10.80	0.00	8.00	8.00
	23	25	25.00	26.70	23.30	0.00	6.80	6.80
	27	15	15.00	14.60	12.10	0.00	2.67	19.33

Values indicate the added noise level in mode shapes. The noise level in natural frequency is taken as one tenth of that of mode shapes.