基于分离法,以车轮与桥面板接触点为界,将车-桥耦合振动系统分为车辆、桥面平整度及桥梁结构3个子体系,分别建立空间耦合振动分析模型及各自的运动方程;车辆体系与桥梁体系之间通过车轮和桥面接触处的位移协调条件、车-桥相互作用力的平衡关系相联系,采用迭代法求解系统响应,并以此为基础,借助VB语言编译了随机车流作用下车-桥耦合振动分析程序。以某双曲拱桥为对象,研究了随机车流特性、桥面平整度及桥梁结构参数变化对车-桥耦合振动的影响。结果表明:除结构自身刚度外,桥梁结构的动力响应受车流特性、桥面平整度等参数的影响明显,桥梁结构拱顶、中跨1/4处及拱脚等部位对应的冲击系数存在明显差异,结构内力与位移对应的冲击系数也不尽相同。
Based on separation method,regarded wheel and bridge panel contact point as fringe,the vehicle-bridge coupled vibration system was divided into three sub-systems,including vehicle,bridge surface flatness and bridge structure.Each space coupled vibration analysis model and its equation of motion were established.The vehicle system was connected with the bridge system through displacement coordination between the wheel and the bridge surface,and the balance of interaction between vehicle and bridge.Iterative method was used to explain system response.On the basis of it,the vehicle-bridge coupled vibration analysis program under random traffic flow was compiled with the help of VB language.Regarded a two-way curved arch bridge as the studying case,influences on the vehicle-bridge coupled vibration caused by the random traffic flow characteristics,bridge surface flatness and the change of bridge structure parameters were conducted.The results show that the dynamic response of the bridge structure was obviously influenced by the parameters,such as the traffic flow characteristics,and the bridge surface flatness,but the influence of structure stiffness is very small.There is a clear difference for the corresponding impact coefficients to the bridge structure arch crown,1/4 mid-span and arch foot and the corresponding impact coefficients of the structure internal force and the displacement are not same.