Research On Lateral Stability Of Speed-Raising Railway Vehicles And Its Application

To meet the demand of railway transportation, the speed-raising rolling stock, which is a key component of railway equipments, is developed in succession by the Ministry of Railway in China. With the increase of running speed, the reliability of some key components declined and the running performance of speed-raising rolling stock was worsened. These problems have endangered the safety of operation. The most serious problem is that the lateral dynamic performance cannot meet the speed-raising demand in presentation of deteriorated lateral running stability. So the lateral running stability of speed-raising rolling stock has become an urgent subject to be solved in the great-leap-forward development of Chinese railways.This thesis briefly reviews the history and current situation on the study of lateral stability fields of classical dynamics and vehicle-track coupled dynamics in China and other countries. According to the vehicle-track coupled dynamics and its scientificity and dependability in the study of lateral stability, the research approach to investigate the lateral stability of speed-raising vehicles running on elastic tracks is drafted by combination of numerical analysis and experimental test.The validity and perfection degree of the vehicle-track coupled dynamics model play decisive roles in the dependability and accuracy of the simulation results. According to the structural characteristics of speed-raising rolling stock, the dynamic models of speed-raising rolling stocks were set up and modified in this paper. In these models, the rolling stocks are regarded as the multiple rigid body system, all kinds of movements of the car body, bogie and wheel-set, and various non-linearity factors in vehicle suspension system are fully considered. Dynamics model of ballast track is used in vehicle-track coupled dynamics model.Wheel/rail interaction is the connection between the rolling stock and track. This thesis quotes the principles of wheel/rail spatial geometric constrains, wheel/rail Hertz non-linear elastic contact theory, and wheel/rail creep theoryWith various kinds of analytic tools, the effects of parameters of vehicle on its lateral stability are analyzed and technical support is offered by the systematical research results. The effect of assembling errors of vehicle components on the lateral stability is analyzed tentatively and finally the reference is offered for overhauling and the wear limit in future. Meanwhile, experimental test is carried out to study the effect of wear status on the lateral stability.In this thesis, dynamic performance of the speed-raising locomotive SS7E,120km/h speed-raising freight wagons, and 160km/h fast container flat car are analyzed detailedly using the train-track dynamics simulation software TTISIM and the numerical results are verified by the field test results. The software of NUCARS and SIMPACK were also used to analyze lateral stability of the 120km/h truck.Some results are obtained from this study. As to the lateral stability of the locomotive close attention should be paid to the primary suspension stiffness and shock absorber as to the speed-raising vehicle, close attention should be paid to the status of the shock absorber, primary suspension rigidity and side bear; as to the 160km/h fast container flat car, close attention should be paid to the primary suspension stiffness as well as the turning resistance moment of the side bear.