应用碳纤维索的大跨径斜拉桥抗风性能研究

为了探讨碳纤维复合材料在大跨径斜拉桥中应用的可能性,以拉索等轴向刚度为原则,拟定了一座主跨为500 m的应用碳纤维索的大跨径斜拉桥,并运用三维非线性计算理论进行了动力特性、静风特性和空气动力稳定性分析。分析结果表明大跨径斜拉桥采用碳纤维索后:(1)结构的自振频率有所提高;(2)静风作用下结构变形增大,但其静风性能却与钢索斜拉桥基本一致;(3)空气动力稳定性与钢索斜拉桥基本一致。因此从抗风性能角度而言,大跨径斜拉桥采用碳纤维索是可行的,但是拉索截面尺寸应采用等轴向刚度原则来确定。

Research on Wind Resistance Beharior of long Span Cable-Stayed Bridges with Carbon Fiber Reinforced Polymer Stay Cables

To gain possibility of the application of carbon fiber reinforced polymer(CFRP) stay cables used in long-span cable-stayed bridges,a 500 m cable-stayed bridge model with CFRP stay cables is established.The equivalent axial stiffness,the dynamic behavior,the aerostatic behavior and aerodynamic stability of the bridge are analyzed by 3D nonlinear analysis.The results show that after CFRP stay cables are used in long-span cable-stayed bridges:(1) structural natural frequencies are slightly increased;(2) under the static wind action,structural deformation is increased,however its aerostatic behavior is basically the same as that of the bridge with steel stay cables;(3) its aerodynamic stability is very identical to the bridge with steel cables.Therefore as far as the wind resistance is considered,the use of CFRP stay cables in long-span cable-stayed bridges is feasible,and the stay cable's section should be determined by the equivalent axial stiffness.