一类单塔斜拉桥固有频率及模态的计算与分析

发布时间：2018-04-28 20:52

本文选题：斜拉桥 + 连续体系统振动　；参考：《应用力学学报》2016年06期

【摘要】：采用连续体系统动力学分析方法对一类平面单塔斜拉桥的固有频率及模态进行了计算与分析。桥面两端简支,并由一个刚性的塔和两根斜拉索支撑。将桥面简化成梁的模型,建立了各斜拉索及各梁段的动力学偏微分方程、斜拉桥的边界条件及子结构间的几何与力学相容条件。推导了斜拉桥线性化、无阻尼系统的频率方程。考虑斜拉桥左右对称及参数(斜拉索长度、初始垂度)微小变动导致对称性破缺的情况,数值求解不同参数下斜拉桥的固有频率及对应的模态。结果表明:斜拉桥第3阶和第4阶固有频率相差不到0.1%,具有密集固有频率的现象;斜拉桥对称性破缺前后第3阶和第4阶固有频率随参数变化的曲线具有频率曲线偏转现象,第3阶和第4阶模态间存在模态跃迁现象。该研究结果可在斜拉桥设计和建造过程中起参考作用。
[Abstract]:The natural frequencies and modes of a class of plane single tower cable-stayed bridges are calculated and analyzed by means of continuum system dynamics analysis method. The deck is simply supported at both ends and is supported by a rigid tower and two cable-stayed cables. The dynamic partial differential equations of each cable and beam segment, the boundary conditions of cable-stayed bridge and the geometric and mechanical compatibility conditions between substructures are established. The frequency equations of linearized and undamped cable-stayed bridges are derived. Considering the symmetry breaking of cable-stayed bridge caused by small variation of parameters (cable length, initial sag), the natural frequencies and corresponding modes of cable-stayed bridge with different parameters are numerically solved. The results show that the third and fourth order natural frequencies of cable-stayed bridges are less than 0.1 and have dense natural frequencies, the curves of the third and fourth order natural frequencies of cable-stayed bridges before and after symmetry breaking have the phenomenon of frequency curve deflection. There is a modal transition between the third and fourth modes. The results can be used for reference in the design and construction of cable-stayed bridges.
【作者单位】：江苏大学土木工程与力学学院;哈尔滨工业大学航天学院;
【分类号】：TU13;;O327

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