RIDING-COMFORT EVALUATION FOR FE LOCOMOTIVE CAR BODY STRUCTURE BASED ON PSEUDO-EXCITATION METHOD AND SYMPLECTIC ALGORITHM

In this present paper,according to the rigid-flex hybrid model for major finite vehicle-track coupling system,the pseudo-excitation and sympectic method was established for riding quality estimation of the flexible vehicle body.Firstly,the track was regarded as infinite long period chain structure then the orbital dynamics equation of motion with low degree of freedom was established by symplectic algorithm,which solved the influence on dynamic response of system from boundary effects of finite long track structure;secondly,through tight contact theory,the rigid-flex hybrid vehicle dynamics equation and symplectic orbital dynamics equation were coupled.Lastly,though pseudo excitation theory,the track irregularities were transformed into a series of pseudo harmonic track irregularities,which transformed the random vibration problem into steady state response solution.Then symplectic algorithm of harmonic wave propagation in the periodic chain structures was used.The two methods further built the pseudo-excitation and sympectic method for riding quality estimation of the flexible vehicle body.In the numerical example,on the basis of the methods above,riding quality estimation for coupling system in view of ISO2631was conducted.Then the influence from speed,track irregularity,etc.factors on riding quality was discussed.Therefore,some effective reference information was provided for riding quality analysis and parameter optimization of vehicle-track coupling system.