A frequency response functions-based model updating algorithm for condition assessment of in-service bridges

As of 2013, approximately 11% of the bridges in the U.S. are classified as structural deficient with almost ;This research exploits the recent developments in instrumentation, modeling and data collection by implementing a Frequency Response Functions-based algorithm for damage identification and condition assessment of in-service bridges. A Finite Element Model (FEM) of the target structure is updated through model updating so that it captures the experimentally collected data at different stages during the bridge's design life. The location and extent of damage can be inferred through a comparison between the stiffness parameters of damaged and healthy structure. The protocol proposed in this dissertation was successfully validated in a laboratory specimen and a full-scale bridge.;Aspects such as appropriate selection of unknown parameters and frequency points/bands for updating proved essential in achieving a successful model updating scenario. Using FRFs for condition assessment has the potential to be incorporated into the current visual inspection protocols performed at standard intervals on in-service bridges. In addition, it would allow authorities to perform a more effective and objective funding allocation while limiting additional traffic disruptions, life losses and other public safety issues.