1995 · 19 citations · 0 references
EngineeringCivil EngineeringBridge EngineeringCondition AssessmentStructural EngineeringBridge Condition AssessmentModal AnalysisStructural Condition AssessmentStructural Health MonitoringStructural VibrationVibration MeasurementBridge Damage AssessmentBridge Health MonitoringBridge Monitoring SystemsCracksDamage Detection Using Mode ShapesModal TestingSteel Girder BridgesVibration Mode Shapes
Current bridge inspection methods rely largely on visual examination to evaluate bridge condition. Remote bridge monitoring systems (RBMS) using measured structural vibrations are perceived to assist in bridge inspection. Sensitivity of measured modal properties for RBMS is critical for practical application. The purpose of this study was to examine sensitivity of modal parameters in detecting fatigue cracks, including frequencies, damping ratios, mode shapes, and their derivatives. Modal tests were conducted on a 1/6 scale model of a multiple-steel-girder simple-span bridge and on a simply supported fracture-critical steel bridge, including both intact and damaged states. Sensitivity of modal parameters to changes of structural condition was studied, using statistical methods to simulate practical applications. Results indicate that modal frequencies in conjunction with mode shapes may be used to identify the existence of bridge damage or deterioration of interest. However, it is difficult to identify damage locations using these modal parameters.