Research On Local Vibration Of Bridge Deck Of Steel-box Girder In Vehicle-bridge Dynamic Interaction

The large-scale construction of China's transportation system has led to the construction of large-span cable-bearing bridges with rail transit lines,which objectively promotes the in-depth study of vehicle-bridge/orbital dynamic interactions.However,most of the previous studies have focused on the overall dynamic response of structural did not carry out the detailed analysis of the coupled vibration to further study the local vibration of the bridge structure and the dynamic response of the rail vehicle.Aiming at the problems and shortcomings of the member model in the study of vehicle-bridge/track coupled vibration,in order to improve the vibration performance evaluation index of vehicle-bridge system,the refined analysis of the vehicle-bridge/track coupled vibration is carried out in this paper,mainly completing the following Several aspects of work:(1)According to the D'Alembert principle,the spatial vibration analysis model of the four-axle vehicle with secondary suspension is derived.Then the bridge dynamic balance equation and the coupling conditions of the vehicle-bridge system are introduced.Finally,the concept of track irregularity is explained.The refined analysis of bridge/orbit coupled vibration provides a theoretical basis.Finally,the concept of track irregularity is explained,which provides a theoretical basis for the refined analysis of vehiclebridge/track coupled vibration.(2)Based on Integration Platform for Structural Analysis and Assessment(IPSAA),and against the background of track groove beam segments and flat closed steel box girder,the static and modal differences between the plate-shell finite element model and the finite element model are analyzed,and the dynamic response under the action of the moving load train is analyzed to verify the necessity of fine modeling in vehicle-bridge coupling vibration analysis.(3)The theoretical analysis method is used to study the resonance influencing factors and principles of the simply supported beam under the action of moving loads.Then,based on the three resonance conditions of the simply supported beam,the resonance conditions of the bridge deck under the action of moving loads are analyzed.Finally,the Vehicle-Bridge-Wind Dynamic analysis program(VBWD)is used to analyze the influence of different train formation and running speed on the dynamic response of the vehicle-bridge system.(4)Based on the engineering background of the main navigation bridge of the Yangtze River Bridge in Chongming,Shanghai,the frame model and shell model were established to study the local vibration of the bridge deck.Finally,the dynamic response of the axle system to the shell model of different rail vehicles was studied.Contrast with the specification limits.