【摘要】 应用考虑拉索局部振动影响的计算理论,对主跨为1.4km的碳纤维索斜拉桥设计模型进行了结构振动特性分析.从振型、自振频率和振型能量分布等方面比较了碳纤维索和钢索对大跨度斜拉桥结构动力特性的影响以及发生索桥耦合振动的可能性.计算结果表明,轻量碳纤维索自振频率高,全桥的拉索第1阶频率分布在0.43～2.15Hz,普遍高于桥梁主要振型的频率,发生索桥共振的可能性较小;自重大的钢索第1阶频率分布在0.16～0.79Hz,覆盖了桥梁低阶振型的频率,在主要振型中出现了明显的索桥耦合振动现象.根据主要振型的能量比例分布,在竖弯振型中碳纤维索的振型能量比例略小于钢索,这有利于改善斜拉桥结构的振动问题.研究结果证明了碳纤维索在大跨度斜拉桥中具有很好的应用性能.更多还原

【Abstract】 The dynamic characteristics of carbon fiber composite cable (CFCC) in cable-stayed bridge with main span of 1.4 km were investigated by numerical method taking into account the cable local vibration. The natural frequency, modal shape, mode potential energy distribution, modal damping ratio of CFCC cable-stayed bridge were compared with those of steel cable-stayed bridge. The results show that the primary natural frequency of light CFCC is 0.43—2.15 Hz, which is higher than the frequency field of primary modes of the bridge, so the probability of cable-deck resonance is lower; and that the primary natural frequency of steel cables varies between 0.16—0.79 Hz, which covers the natural frequency field of primary modes of the bridge, and the cable-deck resonance occurs. The mode potential energy of CFCC is smaller than that of steel cables in vertical deformation free vibration modes. Analysis results prove the good applicability of CFCC in long-span cable-stayed bridges.更多还原