Case study of three-dimensional aeroelastic effect on critical flutter wind speed of long-span bridges

Abstract

Three-dimensional (3-D) aeroelastic effect is known as the main factor that leads to the discrepancy between the critical flutter states predicted by two-dimensional (2-D) deck section and 3-D full structure. The 3-D aeroelastic effect on flutter performance of long-span bridges was investigated through historical experimental data statistics, numerical flutter analysis and wind tunnel tests. The critical flutter wind speeds of 16 long-span bridges were statistically analyzed. Subsequently, numerical flutter analysis were conducted towards a 300m-span quasi-simply supported beam bridge, and the 3-D structural effect and the effect of additional static wind angle of attack were analyzed. Corresponding section and full aeroelastic model tests were both carried out for further investigation of 3-D aeroelastic effect. Real-bridge experimental results show that the 3-D aeroelastic effect may lead to a maximum relative deviation in critical flutter wind speed of more than ±30%. Numerical-analysis-based 3-D aeroelastic effect with the contribution of both the 3-D structural effect and the effect of additional static wind angle of attack presents positive but weak influence, while the test results present more significant 3-D aeroelastic effect. Some potential factors, such as the spatial correlation and amplitude-dependency of aerodynamic forces, may also play an important role in 3-D aeroelastic effect.