Experimental study on aerodynamic derivatives of a bridge cross-section under different traffic flows

• Present a progressive identification approach for the estimation of flutter derivatives.
• Investigate the influence of vehicles on the flutter derivatives.
• The impacts of vehicles under different traffic flows on some flutter derivatives are significant.

The presence of traffic on a bridge deck has an important primary impact on the bridge cross-section׳s aerodynamic configuration, which may affect the static force coefficients and the aerodynamic derivatives that will in turn influence the self-excited forces acting on the bridge. Compared to the investigations of the traffic effect on the static force coefficients, its effect on the aerodynamic derivatives is rather rarely studied. In the present study, the forced vibration device is adopted in the wind tunnel to test a scaled bridge section model with vehicle models distributed on the bridge deck considering three simulated traffic flows. The influence of vehicles of different traffic flows under different wind attack angles on the aerodynamic derivatives of the bridge with the reduced wind velocity are investigated based on the experimental results. The measured results show that the influence of vehicles on the aerodynamic derivatives of the bridge cannot be ignored. The impacts of vehicles under different traffic flows on the aerodynamic derivatives are different for different aerodynamic derivatives. The effect of vehicles on the aerodynamic is different for different wind attack angles and different for different traffic flow conditions at a certain attack angle.