Aerodynamic stability of long span suspension bridges with low torsional natural frequencies

作者：Andersen Michael Styrk^*; Johansson Jens; Brandt Anders; Hansen Svend Ole

来源：Engineering Structures, 2016, 120: 82-91.

DOI：10.1016/j.engstruct.2016.04.025

• Long-span bridge
• Flutter
• Torsional divergence
• Aerodynamics
• Wind-structure interaction
• Aeroelasticity
• Wind tunnel experiments
• Non-flutter design principle

Classical flutter of suspended bridge decks can be avoided if the torsional frequencies are lower than the vertical. Wind tunnel tests of single boxes and twin box section models with torsional natural frequencies above and below the vertical frequency has been conducted. Flutter was avoided in all tests where the torsional frequency was lower than the vertical. But too low torsional stiffness caused large static displacements of the girder at medium-high wind speeds and steady state oscillations driven by a combination of torsional divergence and stalling behavior at the critical wind seed. In order to design aerodynamically stable suspension bridges with low torsional natural frequencies it is suggested to increase the mass moment of inertia and provide adequate torsional stiffness by the main cables spacing.

• 出版日期2016-8-1