Probabilistic flutter analysis of bridge considering aerodynamic and structural parameter uncertainties

Abstract

Flutter analysis that governs the bridge aerodynamic instability is crucial during the wind-resistance design period of long-span bridges. However, randomness existing in the wind load and structure can bring about obstacles in the determination of the flutter onset and thus can lead the bridge to precarious situations. Probabilistic analysis considering the uncertainties from different sources is necessary for the risk assessment of bridge flutter. In this paper, a framework for probabilistic analysis of bridge flutter is developed. Bimodal coupled flutter serving as the classical flutter problem is considered. In the probabilistic analysis, modal damping ratio and critical wind speed are reformulated with generalized flutter analysis, based on which their moments are estimated by adopting point estimate method. The proposed framework is validated with experimental data. Results show that both the accuracy and efficiency can be retained.