Flutter Control Effect and Mechanism of Closed Railing Aerodynamic Measure for Bridge

Abstract Through the wind tunnel test, the flutter control effect and mechanism of partly closed railing aerodynamic measure were studied. After taking effective pneumatic measures, the aerodynamic derivative $A₂^*$ A₂^∗ was changed from positive to negative forming aerodynamic damping, which increases the total damping of the bridge. The flutter frequency reduced and the critical wind speed of the flutter increased.

The flutter type of the bridge is a damp driving in which the reversal of implicated movement is dominant. The performance of the main beam flutter was improved through increasing torsional movement of pneumatic positive damping A and reducing torsional coupling movement implicated generated aerodynamic negative damping term D. The degree of participation of the vertical bending freedom and the bending-torsion coupling was increased when the flutter occurs of the partly closed railing aerodynamic measures beam, and the fluttering shape was transferred from the single degree of freedom torsional vibration to the bending and torsional coupled vibration.

Thereby, the flutter frequency was reduced and the critical flutter wind speed was improved.