Flutter characteristics of bridges under non-uniform wind speed

Abstract

Increasing the bridge span reduces the aerodynamic stability of a bridge’s structure, and the complex wind environment in mountainous areas makes wind-resistant designs of bridges more difficult. The flutter response of bridges under a uniform flow field has been extensively studied. However, there are still various blind areas regarding the impact of non-uniform inflow on the aerodynamic stability of structures. Because of the increasing complexity of wind fields at bridge sites in mountainous areas, further investigation of the wind resistance characteristics of bridges under inhomogeneous wind fields is required. The non-uniform wind speed distribution model is first summarized in this paper, and the research conditions are set based on it. Considering a simply supported beam bridge and suspension bridge as the research objects, the flutter responses of the two bridges under the set conditions were explored, and their likenesses were compared. The analysis results demonstrate that the flutter stability of the bridge is reduced under non-uniform wind speed; therefore, the non-uniformity of wind speed cannot be completely ignored in the wind resistance design. The degree of influence of wind velocity non-uniformity on structural flutter stability hardly changes with the change in angle of attack (AOA), which can be used to simplify the bridges wind resistance design under a nonuniform inflow.