随机车流作用下桥梁冲击系数分析

为研究交通车辆作用下在役桥梁的振动特征,需提出随机车流作用下桥梁的冲击系数计算方法.根据响应面分析方法拟合了影响面的函数表达式,求得随机车流作用下桥梁结构最大静挠度;基于已编制的车-桥耦合振动分析程序,获得各类车型单独作用下车-桥耦合接触力,用该耦合接触力等效代替各类车辆三维模型作用在桥梁结构上,从而获得随机车流作用下桥梁结构的动力效应,并求得相应冲击系数,从而提出了简便且实用的随机车流作用下桥梁结构冲击系数计算方法.通过与规范计算值对比表明,本文所提出的方法能有效地计算随机车流下桥梁的冲击系数.

Impact Factor Analysis of Bridges under Random Traffic Loads

To study the vibration characters of the bridge in-service, the impact factor of bridge structures under random traffic loads was presented. The method of influence surface was firstly used to simulate the functions, which was used to obtain the max-value of static displacements by solving the max-value of the function. Secondly, based on each three-dimensional vehicle model and the program of the vehicle-bridge coupled system, the impact forces between each vehicle and the bridge were obtained and then used instead of the whole three-dimensional vehicles in the simulating random traffic loads. And finally, a new method of calculating the impact factor under random traffic loads was obtained and verified. Compared with the impact factor obtained by the Chinese bridge standard and the above method, the results have shown that the proposed method can effectively calculate the impact factor of bridge structures under random traffic.