车流作用下简支桥梁的随机振动分析

Random Analysis of Simple Beam Bridges Under Vehicle Flow Loads

考虑到过桥汽车的重量具有随机性，给出了车流对桥梁作用的随机分布力模型，导出了相应的空间－时间相关函数及空间相关功率谱密度函数。针对简支型桥梁，推导出了随机车流作用下桥梁挠度响应的数字符征函数。通过算例，揭示了简支型桥梁在随机车流作用下挠度响应的方差与车速、车距之间的关系。

Consideriag the ramdomness of vehicle weights, the random distributive load model of bridges is preseated in this paper. The coresponding space - time relation function and space relative spectrum density function are derived. The characteristie function of bridge' s random deflection under . random vehicle flow load is induced whea bridge is modeled as a simple beam. The relation of deflection variance, vehicle speed and distance between two cars is revealed in example. This paper provides theoretical basis for considering the load effect of vehicle flow in bridge design.