应用碳纤维缆索的大跨度悬索桥抗风稳定性研究

为了探讨碳纤维复合材料缆索在大跨度悬索桥中应用的可能性,以主缆等轴向刚度为原则,拟定了一座主跨为1490m的碳纤维复合材料主缆悬索桥,并运用三维非线性计算理论进行了空气静力和动力稳定性分析。通过与同跨度钢主缆悬索桥的比较,讨论了不同主缆材料对大跨度悬索桥抗风稳定性的影响。分析结果表明:大跨度悬索桥采用碳纤维复合材料主缆后,静风作用下结构的变形增大,但其静风稳定性却与钢主缆悬索桥基本接近;由于结构自振频率特别是扭转频率有显著的提高,使得其空气动力稳定性要比钢主缆悬索桥好。因此从抗风稳定性角度而言,大跨度悬索桥采用碳纤维复合材料主缆是可行的,但是主缆截面尺寸的确定应采用等轴向刚度的准则。

Wind stability of long-span suspension bridges using carbon fiber reinforced polymer cables

To understand the applicability of carbon fiber reinforced polymer(CFRP) cables for long-span suspension bridges,the aerostatic and aerodynamic stability of a suspension bridge having a main-span of 1490m using CFRP cables is studied by using 3-D nonlinear analyses.The cross-sectional area of the cables is determined by the principle of equivalent axial stiffness.In comparison with a bridge using steel cables,the effects of different cable materials on wind stability of the bridge are discussed.The results indicate that with CFRP cables,the structural deformation of long-span suspension bridges is increased under static wind action.However,the aerostatic stability of the bridge is basically the same as that of the bridge using steel cables.On the other hand,due to the remarkable increase in torsional frequency,the aerodynamic stability of the bridge is superior to that of the bridge using steel cables.Therefore as far as wind stability is concerned,the use of CFRP cables in long-span suspension bridges is feasible,and the cross-sectional area of the cables should be determined by using the principle of equivalent axial stiffness.