Aeroelastic behavior of long-span suspension bridges under arbitrary wind profiles

The aeroelastic behavior of suspension bridges under generic temporal and space wind distributions is studied employing a parametric one-dimensional structural model coupled with a strip-based indicial representation of the unsteady aerodynamic loads. The aeroelastic response to spatially nonuniform gusts is also investigated. The equations of motion linearized about the prestressed aerostatic equilibrium are expressed in terms of incremental kinematic variables. The aerodynamic loading characteristics of the deck cross sections of the Runyang Suspension Bridge (over the Yangtze river in China) are evaluated by means of computational fluid dynamics simulations performed to extract the aeroelastic derivatives from which the indicial aerodynamic representation is obtained. The aeroelastic equations of motion are then reduced to the state-space ordinary differential form by using the Faedo-Galerkin approach. The reduced-order bridge dynamics and the description of the aerodynamic loading via the added aerodynamic states are solved simultaneously by using a time-integration numerical scheme. Dependence of the flutter condition and the transient response to gusts is shown through systematic parametric studies.