Modeling Vortex -Induced Vibration of Long -Span Bridges

261 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006.The goal of this research was to develop a suitable model, complementary to those existing for flutter and buffeting, which improves current techniques for the prediction of vortex-induced vibration of non-circular sections representative of bridge decks. Wind tunnel experiments of six spring-mounted rigid section models were performed in order to further advance the understanding of the mechanism of vortex-induced vibration of non-circular sections. A practical semi-empirical model that captured the salient features observed in the above investigations was developed and a procedure for extracting the aeroelastic coefficients of the model was developed. The mathematical model developed for a spring-mounted rigid section was extended for flexible, three-dimensional prototype structures through modal analysis. Additionally, spanwise loss of correlation of the aeroelastic coefficients was incorporated in the model. Long-term, full-scale data measured on the Fred Hartman Bridge (a cable-stayed bridge) were analyzed to detect incidents of vortex-induced response using several criteria that were proposed in this study. The full-scale data were also used to identify the modal damping ratio and frequency of the bridge. Finally, the vortex-induced response of the Fred Hartman Bridge was predicted using the analytical model; the predicted responses demonstrated good agreement with the full-scale responses.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD