实际交通流作用下的车-桥耦合振动研究

Study of Vehicle-bridge Coupling Vibration Under Actual Traffic Flow

采用数值方法研究某悬索桥的动力放大系数,完善了公路随机车流下的车-桥耦合振动分析系统,建立了多线程路面粗糙度的模拟技术。推导了多车轴车辆模型的运动方程,并将新的车辆动力学模型嵌入到随机车流下的车-桥耦合振动分析系统中,研究了多线程相关路面粗糙度的模拟技术,并利用快速傅里叶变换提高谐波合成模拟的效率,最后分析了车流作用下大桥的冲击效应,探讨了车-桥耦合振动效应的影响。结果表明:车流作用下,悬索桥的冲击效应明显,耦合效应使振动响应产生了一定相位差,但耦合效应没有引起主梁振幅的大幅增加;悬索桥的动力放大系数宜参照英国BS 5400规范或加拿大OHBDC.1982规范的相关规定进行取值;车速对动力放大系数有显著影响。

In order to study mathematically the dynamic magnification factors of a suspension large bridge,the current vehicle-bridge coupling vibration analysis system under highway stochastic traffic flow was improved,and the random simulation technology of multi-path surface roughness was built.The dynamic equations of multi-axle vehicles were deduced and further embedded into the vehicle-bridge coupling vibration analysis system.The random simulation technology of multi-path surface roughness was studied,and fast Fourier transform was used to promote the efficiency of the harmonic wave synthesis algorithm.The impact effect of traffic flow on the large bridge was analyzed and the influence of vehicle-bridge coupling vibration effect was discussed.The results show that the impact effect of traffic flow on suspension bridges is obvious and the coupling vibration effect leads to the phase variation of the vibration responses.However,with regard to the bridge main beam,coupling effect does not make vibration amplitude increase significantly.It is more reasonable to take the values of the dynamic magnification factors of a large suspension bridge according to BS 5400 or OHBDC.1982.The influence of driving velocity on dynamic magnification factors is evident.