FATIGUE ANALYSIS OF COMPOSITE HIGHWAY BRIDGE DECKS

Steel and composite (steel-concrete) highway bridges are usually subjected to dynamic actions of variable magnitude due to vehicles crossing on the deck pavement.These dynamic actions can generate the nucleation of fractures or even their propagation on the bridge structure.Depending on the magnitude and intensity of these actions, these effects may compromise the structural system response reliability that could also lead to a reduction of the expected bridge service life.Therefore, this investigation aims to develop an analysis with emphasis to evaluate the stresses through a dynamic analysis of composite highway bridge decks including the action of convoy of heavy vehicles.The investigated highway bridge is constituted by four longitudinal composite girders and a concrete deck, spanning 40m.The developed computational model adopted the usual mesh refinement techniques present in finite element method simulations implemented in the ANSYS program.The analysis methodology and procedures presented in the design codes were applied to evaluate the fatigue of the bridge determining the service life of the structure.The main conclusions of this investigation focused on alerting structural engineers to the possible distortions, associated to the steel and composite bridge's service life when subjected to vehicle's dynamic actions.