考虑桥梁几何非线性的风-车-桥耦合振动分析

考虑桥梁结构的几何非线性因素,建立了风及列车荷载作用下大跨度桥梁的振动分析模型。以某大跨度三拱连续钢桁梁桥为例,分析了脉动风及静风荷载的不同作用效应,风速、车速变化以及结构几何非线性对桥梁振动响应的影响。结果表明:在进行车桥耦合振动分析时要综合考虑风荷载的动力作用；几何非线性因素会影响桥梁振动的极值,但不影响其变化趋势；风速及车速变化对桥梁位移极值均有较大影响。

COUPLING VIBRATION ANALYSIS OF WIND-TRAIN-BRIDGE SYSTEM CONSIDERING GEOMETRIC NONLINEARITY OF BRIDGE

Taking into account the geometric nonlinearity of structures, the dynamic analysis model for long-span bridges under train and wind actions is established. A long-span continuous steel trussed bridge is taken as an example to analyze the load effects of static wind and buffeting wind, the influence of wind velocity and train speed and the effect of geometric nonlinearity. The results show that the wind loads should be considered in analyzing the train and bridge system;the geometric nonlinearity affects greatly the maximum deflections of bridge, but it does not change the tendency of displacement histories;both wind velocity and train-speed have great influence on the maximum deflection of the bridge.