Research On The Mechanical Performance Of Curved Beam Bridges Considering Coupled Vibration Of Horizontal And Vertical Vehicles And Bridges

The "lateral creep" disease of highway curved beam bridges is frequent,which in severe cases leads to the detachment and shear failure of bridge bearings,cracking of bridge piers,and crushing of retaining blocks.Vehicle load is an important external cause of "lateral creep" of curved girder bridge.The displacement of curved girder bridge is calculated by applying vehicle load to the bridge according to the traditional Statics method,ignoring the transverse and vertical vibration characteristics of vehicles and curved girder bridge.The results obtained are difficult to reflect the actual stress state and response of curved girder bridge.At the same time,there are few research results on the transverse and vertical coupled vibration of vehicle curved girder bridge.Based on this,this article studies the precise stress and response of curved beam bridges considering the coupling vibration effect of horizontal and vertical vehicles and bridges.The main research content and work of this article are as follows:(1)Establishment of axle system.The Equations of motion of the 12 DOF vehicle model are derived by using d’Alembert principle;Newmark-beta method program was developed using ANSYS/APDL language,and specific program code was provided;A finite element model of a certain overpass ramp bridge was established using the shell 63 element.A solution was provided for the problem of node coordinate system during the finite element model solving process of a curved beam bridge.The dynamic characteristics of the curved beam bridge model were preliminarily analyzed using the block Lanczos method.(2)Simulation of road roughness.The discrete power Spectral density data in a certain spatial frequency are obtained within the natural frequency and speed of the vehicle concerned,and the A/B/C level road roughness data are generated using the inverse Fourier transform technology.The theoretical power Spectral density and the actual power Spectral density of the generated road roughness are compared,and the theoretical and actual power Spectral density images are in good agreement.(3)Implementation and verification of lateral and vertical coupling vibration of vehicle bridges.Based on the principle of vertical coupling vibration of vehicle bridges,a coordination equation for displacement and force of lateral coupling vibration of vehicle bridges was established.The solution process for solving lateral and vertical coupling vibration of vehicle bridges in an ANSYS environment was presented.The solution program in this paper was validated based on relevant literature data,and the results showed that the solution program in this paper has good convergence and accuracy.(4)Accurately calculated the lateral force of the curved beam bridge,namely the lateral coupling vibration force of the vehicle bridge and the varying centrifugal force of the vehicle.The results were compared with the lateral force of the bridge under traditional analysis methods.The results showed that the coupled vibration force of the vehicle bridge accounted for about 10% of the total lateral force,and the varying centrifugal force of the vehicle accounted for about 90% of the total lateral force.Considering the lateral and vertical coupling effect of the vehicle bridge,the lateral force on the curved beam bridge increased compared to traditional analysis methods.(5)The lateral displacement and support reaction response of curved beam bridges under different lateral force research methods were calculated.The analysis shows that considering the lateral coupling vibration of the vehicle bridge and the changes in vehicle centrifugal force exacerbates the lateral vibration of the curved beam bridge,resulting in an increase in the lateral dynamic response of the curved beam bridge compared to traditional analysis methods.When studying the effect of vehicle load on the curved beam bridge,the lateral coupling vibration of the vehicle bridge and the changes in vehicle centrifugal force should be considered.(6)Under the lateral force research method that considers the coupling vibration effect of lateral vehicle bridge and the variation of vehicle centrifugal force,the lateral and vertical displacement and support reaction response of curved beam bridges were calculated under parameters such as road roughness,vehicle weight,vehicle speed,and eccentric driving.Furthermore,the influence of the above parameters on the lateral and vertical dynamic response of curved beam bridges and the friction slip between the bridge and the support were analyzed.