Rigid-flexible Coupling Dynamics Analysis Of Vehicle-Bridge-Road Based On Steel-Concrete Bridge Pavement

With the rapid development of expressway in China,the construction,theory and key construction technologies of expressway bridges have also made remarkable achievements.In expressway construction,steel-concrete bridge is widely used because of its unique advantages.Because the dynamic coupling effect of steel-concrete bridge structure is more prominent than that of reinforced concrete bridge structure,fatigue cracks and cracks are more likely to occur in bridge asphalt pavement under vehicle load,which affects the service life of bridge asphalt pavement.Therefore,vehicle-bridge-road coupling of steel-concrete bridge is carried out.The study of combined dynamics has important theoretical significance and engineering application value.In the existing vehicle-bridge-road research,the vehicle model is simplified as moving load,wheel load or spring-mass-damp simulation;the coupling between vehicle,road surface and bridge is not considered,and the unified model is not established,which makes it difficult to reflect the coupling characteristics of the whole system.In this paper,a steel-concrete composite shaped steel bridge of an expressway is taken as the research object.The finite element model of the bridge and Pavement is constructed by the finite element software Ansys.The dynamic inherent vibration characteristics of the system are obtained.The multi-rigid-body real vehicle model is established by the dynamic software UM,and the vehicle-bridge-road rigid-flexible coupling system dynamic model is established in UM.According to the pavement irregularity standard,the irregularity pavement spectrum is constructed.The influence of vehicle load and speed on the deflection,impact coefficient,transverse tension stress,longitudinal tension stress and shear stress of Pavement layer in the vehicle-bridge-road rigid-flexible coupling system is studied.The variation law of dynamic response Parameters of bridges is analyzed.When vehicles Pass through bridges with different loads and speeds,the dynamic response parameters of bridges are divided into three parts.The dynamic load response of vehicle front axle and mid axle and the vertical force response of front and mid axle are analyzed.The correctness of vehicle-bridge-road rigid-flexible coupling system and the validity of the calculation results are verified by comparing the results of bridge field modal test and deformation test with those of calculation.