Análise dinâmica e verificação à fadiga de obras de arte rodoviárias mistas (aço-concreto) submetidas ao tráfego de veículos sobre o pavimento irregular.

Abstract

Steel and steel-concrete composite highway bridges are currently subjected to dynamic actions with variable magnitudes due to the action of vehicles crossing on the deck. These dynamic actions can generate the nucleation of fractures or even their propagation in the structures. Depending on the magnitude, these effects can compromise the structural system response and the reliability, which may also lead to a reduction of the expected bridge service life. This way, the dynamic response of a steel-concrete composite bridge spanning 40 m was investigated in this work. The computational model, developed for the composite bridge dynamic analysis, adopted the usual mesh refinement techniques present in finite element method simulations, and was implemented in the ANSYS program. A parametric study was performed to identify the effect of vehicle speed and roughness pavement on the investigated bridge dynamic behaviour. The proposed methodology for evaluate the bridge service life to fatigue was based on a linear cumulative damage rule, Rainflow-counting algorithm and S-N curves from main design codes. Results of a parametric analysis are presented to verify the extension of the dynamical effects on highway bridges due to vehicles crossing on the irregular pavement surface. The main conclusions of this work focuses on alerting structural engineers to the possibility of increase of fatigue damage, related to steel and composite highway bridges when subjected to vehicle dynamic actions.