Cross-seat Light Rail Vehicles And Public Rail Dual-use Large Bridge In The Car At The Same Time Under The Dynamic Response And Driving Comfort

With the development of economy, traffic problems in major cities have presented important needs of more safe, efficient and reliable transportation systems. On one hand, more and more bridges have been desiged to carry both vehicle and railway traffic; on the other hand, the traffic volume has increased dramatically, and new transportation tools such as monorail train have been put into operation. Dynamic performances of long span bridges and vehicles under both moving monorail trains and road vehicles and riding comfort of monorail trains and vehicles have become problems of great concern to many engineers. However, only a little research about dynamic responses of bridges and monorail trains interaction system has been addressed publicly. What's more, few studies of coupled monorail train-car-bridges system have been conducted to investigate dynamic performance of this system.This thesis mainly focuses on the development a framework for dynamic analysis of bridge-monorail train-vehicle interaction system and evaluation of the riding comfort of monorail trains and vehicles. The major work has been done in this thesis as follows:First, models of heavy road vehicles and monorail trains have been built using mass-spring-damper system respectively. The heavy road vehicles have been modeled as a mass-pring-damper system with 7 degree of freedom (DOF), while the DOF of the monorail train model is 15.Second, the surface roughness of bridge decks and monorail tracks is simulated. The surface roughness is taken as stationary stochastic process and then it is simulated using spectral representation method.Third, a framework for the coupled bridge-monorail train-vehicle system taking account of surface roughness has been developed. Bridges, monorail trains and vehicles are integrated as a whole coupled system, and then the virtual work principle and fully computerized approach for assembling matrices are applied to establish the governing equation of the coupled system. Fourth, the riding comfort criteria stipulated in the document ISO2361 issued by the International Standard Organisation (ISO) have been introduced. Then the riding comfort can be evaluated by using the 1/3 octave band spectra of monorail train's and vehicle's acceleration response compared with the fatigue-decreased proficiency boundary for the riding quality level of ISO2361.Fifth, an assocatied program was developed for dynamic analysis of coupled bridge-monorail train-vehicle system using Fortran 95. It can simulate dynamic responses of bridges, monorail trains and vehicles of arbitrary numbers and various types under monorail trains and vehicles running with different surface roughness, velocities and lanes in time domain. Two classic cases have been studied to prove the accuracy of this program.Finally, the dynamic analysis of the Caiyuanba bridge under moving monorail trains and heavy road vehicles coupled system has been conducted. A finite element model of the Caiyuanba bridge has been built, then its dynamic properties has been computed. After that, dynamic analysis of three bridge-vehicle interaction systems including Caiyuanba bridge bridge-road vehicle interaction system, Caiyuanba bridge-monorail train interaction system and Caiyuanba bridge-monorail train-road vehicle interaction system has been performed and riding comfort of corresponding monorail trains and vehicles has been estimated. Results show that the Caiyuanba bridge has good lateral and vertical stiffness and it can satisfy the ride comfort of the monorail trains and vehicles in the normal operation.