双索悬索桥自振特性分析

以黄河大峡水库下游某双索悬索桥为工程背景,引入只受拉三维拉索单元,采用考虑几何非线性的子空间迭代法对其自振特性进行了分析,理论值与实测值能较好的吻合,说明了该空间非线性有限元分析方法的正确性;进而与相同跨径和结构参数的单索悬索桥的自振频率、振型进行了对比分析,结果表明双索悬索桥能有效提高桥梁一阶竖弯振动频率,为双索悬索桥结构设计理论提供了动力性能方面的依据.

Analysis of Natural Vibration Characteristics of Double Cable Suspension Bridge

Taking the double cable suspension bridge near the Daxia Reservoir which is at the lower reach of the Huanghe River as an engineering example, using 3-D tension-only element and adopting subspace iteration method,the natural vibration characteristics of suspension bridge is analyzed. The calculation results coincided with the experimental data mean that the analysis method which considering geometrical nonlinearity is correct. Based on these, the natural vibration characteristics of both double cable suspension and single cable suspension which have the same structure parameters are calculated, and the result comparison shows that double cable suspension can attain higher vertical base frequency. The conclusion of this paper can provide dynamic characteristics basis for the design theory of double cable suspension bridge.