Vibration-based damage identification and health monitoring of civil structures

Civil structures undergo progressive deterioration due to ageing under the effects of environmental conditions. This deterioration has become a worldwide concern. In addition, natural and man-made hazards such as earthquakes, hurricanes, and explosions can also cause structural damages or exacerbate existing damage. Vibration-based structural damage identification and health monitoring has been the subject of significant research in structural engineering over the past decade.; The research work presented in this dissertation consists of: (1) a comparative study of output-only system identification techniques as applied to the Alfred Zampa Memorial Bridge based on dynamic field test data, through which the performance of different output-only system identification methods applied to the bridge vibration data and corresponding to different excitation sources is investigated; (2) development of a simulation framework for wind-induced ambient vibration response of Vincent Thomas Bridge using a detailed three-dimensional finite element model of the bridge and a state-of-the-art stochastic wind excitation model, which provides a validated framework to study the effects of realistic damage scenarios in long-span cable-supported bridges on their identified modal parameters; (3) damage identification of a full-scale seven-story reinforced concrete building slice tested on the UCSD-NEES shake table using a sensitivity-based finite element model updating strategy based on the modal parameters identified from ambient vibration data; (4) development and implementation of a state-of-the-art long-term continuous monitoring system on the Voigt Bridge Testbed, which will serve as a live laboratory for structural health monitoring technologies; (5) development of an automated system identification procedure for extracting modal parameters of the Voigt Bridge as a function of time; and (6) investigation of the environmental effects on the identified modal parameters of the Voigt Bridge and objective criterion for damage detection under varying environmental conditions.; The research work presented and the results obtained in this dissertation contribute significantly to the development of robust and reliable vibration-based structural health monitoring systems for large and complex real-world structures.