Structural Health Monitoring of Precast Concrete Box Girders Using Selected Vibration-Based Damage Detection Methods

Table 3

Error in predicted damage location by each method, listed as a fraction of measurement point spacing, when 15 and 79 measurement points were used.

Method	15 points				79 points
	Max. error	Avg. error	Stand. dev.	% ambig*	Max. error	Avg. error	Stand. dev.	% ambig*
CMS	0.30	0.12	0.06	0	0.50	0.50	0.003	0
DI	0.50	0.26	0.15	0	0.50	0.50	0.001	2.5
MCF	0.50	0.20	0.14	40	0.50	0.50	0.001	40

*indicates the percentage of the 40 cases that produced a second peak that was either at least 75% of the magnitude of the highest peak, or nearer to the damage location, including near support damage cases.