| In order to provide the theoretical foundation for the application of CFRP in the super large-span suspension bridge, the advantages and disadvantages of using CFRP as the main cables of a super large-span suspension bridge were researched in terms of static and static-dynamic stability in wind. Better structure system and stiffening girder section were studied in terms of wind resistance. The main contents are as follows.The wind resistance theory was firstly described in this paper. A Nonlinear Aerostatic Stability Analysis System (NASAS) and a Step-By-Step Analysis (SBSA) system for two-dimensional coupled flutter were programmed based on APDL language of ANSYS and Visual Fortran respectively. SBSA was verified and the differences of the common three two-dimensional flutter analysis methods, including semi-inverse method, complex modal analysis and step-by-step analysis were analyzed by a classic plate example. A kind of super large-span suspension bridge with steel cables and another one with CFRP cables were compared comprehensively from in terms of static and static-dynamic stability in wind, in order to show the advantages and disadvantages of using CFRP for the main cables in a super large-span suspension bridge.Secondly, structural measures were studied to improve the wind resistance of the super large-span suspension bridge with CFRP cables consisting of design parameters of the conventional suspension bridge and cable systems. The design parameters considered include the ratio of rise to span, the safety factor and the Young's modulus of main cables, the constrained system of stiffening girder, dead load intensity, the stiffness and structural style of the bridge towers, and the area and Young's modulus of hanger. The dynamic characteristics of different cable systems such as cross-hanger system, rigid frame system, spatial cable system, Dischinger cable-stayed suspension bridge system and the three main cables system were studied, and the differences of horizontal, vertical and torsional stiffness of the mentioned cable systems were analyzed. The better locations of auxiliary cables or rigid auxiliary components in these different cable systems were researched by analyzing the Influence Lines of fundamental frequency of lateral bending, vertical bending and torsional. The Influence Lines proposed the economical investment methods to increase the stiffness of different structural systems with less change of structural system.The measures for improving the flutter stability of the super large-span suspension bridge with CFRP cables were finally researched in this paper through studying the aerodynamic shape of the stiffening girder section. The flutter stability and the flutter mechanism of four kinds of stiffening girder section with different aerodynamic shapes to each other, such as closed box section, separated twin-box section, separated three boxes section and elliptical cross section were analyzed based on step-by-step analysis method of two-dimensional flutter and SBSA. In order to improve the flutter stability of the separated twin-box section, four kinds of aerodynamic measures were considered including the separation distance of separated twin-box, wind fairing shape, the settings of guide vane and the width of air distributor applied. It was proved that the flutter stability of the separated twin-box section would be affected greatly by the metioned four aerodynamic measures, both the distance between two separated twin-box and the elevation between the guide vane and section have an optimal value. The flutter critical wind speed of separated twin-box section would not monotonically increase with the decrease of wind fairing angle, however, it shows a decline after increase, and the wind fairing angle has an optimal value. The flutter critical wind speed of separated twin-box section would increase limitedly by setting narrower air distributors, but the flutter stability of the separated twin-box section would decrease with wider air distributors, and its flutter critical wind speed would be much lower than that without air distributors.This study shows that the influence of changing of the design parameters of conventional suspension bridge on the wind resistance of the super lager-span suspension bridge with CFRP cables is limited. However, the flutter stability of the super lager-span suspension bridge with CFRP cables would be enhanced by changing the cable system and the aerodynamic shape of stiffening girder. So that collapse caused by wind dynamic force is no longer the critical factor to restrict applying CFRP cables to super large-span suspension bridge.
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