Time-domain Aerodynamic Model of Aeroelastic Response Analysis of Bridges

In order to solve the low efficiency problem caused by large calculation amount of non-stationary computational fluid dynamics(CFD) used in conventional aeroelastic response of bridges,a novel method was presented which was efficient and expedient to evaluate aeroelastic response of bridge based on time-domain aerodynamic models.Firstly,unsteady aerodynamic forces acting on bridge sections were obtained by using CFD with forced exponential pulse displacement.In order to develop the discrete-time aerodynamic models in time-domain,system identification was applied to displacement input and aerodynamic output of fluid system from the CFD simulation.Then,the obtained aerodynamic models were used in place of the unsteady CFD simulation,which could predict aerodynamic forces acting on the section to bridge displacement.Finally,aeroelastic system of a thin plate with only torsional degree of freedom in wind was employed to predict its aeroelastic response.Results show that the time saving associated with the use of the aerodynamic model in coupled aeroelastic solution is significant,and present method can rapidly predict aeroelastic response of structure at future instant of time.