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

Table 3

Statistical results for damage identification in cantilever beam.

Damage case	Detected damage amounts
	10% @ 5		15% @ 9		10% @ 11		20% @ 15
	Mean	Std. Dev.	Mean	Std. Dev.	Mean	Std. Dev.	Mean	Std. Dev.
Noise free data
Single element	10.00
Two-element	10.00		15.00	0.000
Four-element	10.00		15.00		10.00		20.00	0.00
0.5% noise in natural frequency and 5.0% noise in mode shape data
Single element	9.14
Two-element	9.73		15.20
Four-element	8.46		14.41		9.40		19.47
1.0% noise in natural frequency and 10.0% noise in mode shape data
Single element	11.10
Two-element	11.87		14.07
Four-element	13.66	0.00	13.81		10.30		20.43