A design method of aeroelastic model for long-span three-tower steel truss girder cable-stayed bridges

Traditional design methods of aeroelastic model for bridges do not strictly consider the similarity requirements of the axial and torsional stiffness of bridge towers, and are not suitable for simulating three-tower cable-stayed bridges. Moreover, the damping ratios of the aeroelastic model for steel truss cable-stayed bridges are usually difficult to control. In this paper, a design method of aeroelastic model for long-span three-tower steel truss girder cable-stayed bridge is proposed for the first time. For the bridge tower model, the multiaxial stiffness decoupling is realized by deducing the mechanical principle of the Uniaxial Multi-point Elastic Constraint (UMEC) model. For the steel truss girder model, the simulation of low damping ratio is realized by separating the shape system from the stiffness system. a full-bridge aeroelastic model with a geometric scale ratio of 1/160 was fabricated. The approximate mode shape, frequency and damping ratio of the mode are identified by the time history and phase of the signal. The modal test results and the buffeting characteristics in the turbulent flow field further verify the feasibility and reliability of the proposed design method. The research results can provide valuable reference for the aeroelastic model design and wind resistance research of similar bridges.