Study of Vehicle-bridge Coupling Vibration Under Actual Traffic Flow

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.