Aerodynamics of a stay cable with helical fillets - Part I: Stability and load characteristics

作者：Christiansen H^*; Jakobsen J B; Macdonald J H G; Larose G L; Bosch H R

来源：Journal of Wind Engineering and Industrial Aerodynamics, 2018, 177: 376-391.

DOI：10.1016/j.jweia.2018.01.045

• Bridge stay cable
• Helical fillets
• Inclined circular cylinder
• Cable instability
• Surface pressures
• Sectional loads
• Quasi-steady theory
• Reynolds number

The aerodynamic behaviour of a bridge stay cable with helical fillets in smooth flow at high Reynolds numbers is presented in this paper. The cable response and related sectional load characteristics were studied experimentally on a 1:1 scale cable section model. The studies showed that a cable with helical fillets inclined 60 degrees to the flow could experience large amplitude wind induced vibrations and that the occurrence of vibrations were highly dependent on cable surface irregularities. The ambition is not to explain fully the excitation mechanism, but to present global and local influences of the helical fillets on the flow field. It was revealed that the flow field around the cable shifted between semi-stable transition states which took place when the transition from laminar to turbulent flow propagated from the free shear layers to the boundary layer. The transitions would form locally and spread along the cable axis. The helical fillet appeared to dominate the local flow structures when located at an angular position between 40 degrees and 130 degrees from the stagnation region. In the stagnation and base regions, the surface irregularities appeared to dominate. Furthermore, the helical fillets displaced the mean stagnation line. The application of quasi-steady theory with the measurement data available appeared not to be able to explain the vibrations.

• 出版日期2018-6