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

Table 6

Summary of performance of the three VBDD methods and the influence of the factors studied.

Factors	CMS	MCF	DI
Reference conditions: (i) 7 meas. points; (ii) Fundamental mode	Unambiguous indication of damage location within ±0.8h	Unambiguous indication of damage location within ±0.8ℎ	Unambiguous indication of damage location within ±0.8ℎ
Near support damage cases	Able to locate damage with little ambiguity	Multiple peaks indicating that damage is located near a certain support	Misleading predictions of damage location
Use of additional measurement points	Proportional increase in localization accuracy	Proportional increase in localization accuracy	Proportional increase in localization accuracy
Use of additional modes	No improvement	Reduction in ambiguity for some near support damage cases	Decline in localization accuracy
Combined use of additional modes and additional measurement points	No improvement	No improvement	Some improvement relative to the use of additional modes alone