Analysis Of Vehicle-Bridge Coupled Vibration Of Long-Span Road-Rail Suspension Bridge

Suspension bridges widely exist all over the world because of their excellent spanning ability.However,the dynamic response of suspension bridges has always been the focus of engineering and academia in various countries.In this paper,a series of theoretical derivation and simulation experiments are carried out based on the free vibration and vehicle-bridge coupled vibration of suspension bridges.The main contents include the following aspects.1.Transfer matrix algorithm is proposed for the solution of vertical free vibration of suspension bridge.First,a solution scheme is presented for the governing differential equation of vertical free vibration of suspension bridge,in which the analytic expression of structural free vibration is deduced directly.On this basis,the transfer matrix of the vertical free vibration of suspension bridge analysis is obtained.With this method,the problem of vertical free vibration of both constant cross-section and variable cross-section suspension bridge is studied.Research results indicate that the transfer matrix algorithm analyzes the vertical free vibration of suspension bridge efficiently,and has specific advantages in dealing with the problem about variable cross-section.2.K-L expansion method is introduced into the solution of track irregularity samples.Based on the USA PSD and German PSD,track irregularity samples are obtained respectively.And its accuracy is proved by comparing the results with traditional methord and K-L expansion methord.3.Taking Malinghe steel truss suspension bridge as an example,the dynamic response of suspension bridge under certain excitation is studied,and the main factors affecting the dynamic response of vehicle-bridge coupled vibration is determined by changing the parameters of vehicle mass,vehicle speed,vehicle body stiffness,track vertical irregularities,bridge bending-torsion ratio and height-width ratio.The main factors affecting the dynamic response of suspension bridges and streetcars are determined.4.In this thesis,the dynamic response of suspension bridges under random excitation is studied.And two car tracks and two streetcar tracks are considered.The random excitation includes random vehicle mass satisfying normal distribution and random vehicle space satisfying Poisson distribution.According to the analysis and summary of dynamic response of suspension bridge and streetcar,the effect of random excitation on vehicle-bridge coupled vibration is obtained.