Nonlinear Aeroelastic in-Plane Behavior of Suspension Bridges under Steady Wind Flow

Simona Di Nino, Angelo Luongo
2020 Applied Sciences  
The nonlinear aeroelastic behavior of suspension bridges, undergoing dynamical in-plaininstability (galloping), is analyzed. A nonlinear continuous model of bridge is formulated, madeof a visco-elastic beam and a parabolic cable, connected each other by axially rigid suspenders,continuously distributed. The structure is loaded by a uniform wind flow which acts normally to thebridge plane. Both external and internal damping are accounted for the structure, according to theKelvin-Voigt
more » ... in-Voigt rheological model. The nonlinear aeroelastic effects are evaluated via the quasi-statictheory, while structural nonlinearities are not taken into account. First, the free dynamics of theundamped bridge are addressed, and the natural modes determined. Then, the nonlinear equationsruling the dynamics of the aeroelastic system, close to the bifurcation point, are tackled by theMultiple Scale Method. This is directly applied to the partial differential equations, and provides thefinite-dimensional bifurcation equations. From these latter, the limit-cycle amplitude and its stabilityare evaluated as function of the mean wind velocity. A case study of suspension bridge is analyzed.
doi:10.3390/app10051689 fatcat:35n5xwetorcthp5ykqpslw37ki