Study On Vehicle-bridge Coupling Vibration And Impact Coefficient Based On UM Simulation Analysis

Along with advancement of the major national strategy of integration of Beijing,Tianjin and Hebei,traffic volumes on roads and bridges have increased dramatically in our city,and the impact of vehicles on bridges during driving is also more significant.This impact not only affects the driving safety of vehicles,but also has a certain impact on the bearing capacity of bridges.The problem of interaction between the axle and the vehicle is called the vehicle bridge coupling vibration problem.The definition of bridge impact coefficient in current codes only focuses on the single factor of fundamental frequency,But in actual situation,the impact caused by vehicle bridge coupling can not be ignored.Vehicle speed,vehicle weight,bridge roughness and so on have impact on the bridge.In order to analyze the influence degree of these factors,the representative simple supported beam bridges and continuous beam bridges are selected respectively,and the main research contents and achievements are as follows:1.This paper introduces the theory and formula deduction of vehicle bridge coupling vibration,introduces Universal Mechanism,a new generation multibody system dynamics simulation software,and introduces how it simulates the vehicle bridge coupled vibration model.2.The vehicle model is established by using Universal Mechanism,a new generation multibody system dynamics simulation software;the bridge model is established by using ANSYS,a finite element software,and the finite element model is led into Universal Mechanism to establish the vehicle bridge coupling vibration model.3.In the vehicle bridge coupled vibration model,the influence on impact coefficient is analyzed by changing vehicle speed.It is found that the speed has little influence on the small span simply supported girder bridge,and has certain influence on the continuous beam bridge.4.In the vehicle bridge coupled vibration model,the influence degree of the vehicle weight on the impact coefficient is analyzed by changing vehicle weight.It is found that for both simply supported beam bridges and continuous beam bridges,the weight has great influence on the impact coefficient,and the impact coefficient increases linearly with the weight.5.In the vehicle bridge coupling vibration model,the influence on the impact coefficient is analyzed by simulating roughness levels of different bridge decks.It is found that the impact coefficient of the bridge increases with the decrease of the bridge roughness.6.The linear regression analysis of shock coefficient under different conditions is carried out.The impact coefficient expressions of different deck classification are obtained under the two types of bridges.The regression formula is also tested by the significance test,and the regression degree is good.7.The formula obtained by fitting is compared with the formula in the code.It is found that standard calculation of impact coefficient only distributes in one frequency band and a weight range.It is positively correlated with the fundamental frequency and contrary to the results of this paper.The approximate formula provides a reference for engineering practice,and has certain practical significance.