| High operations speed and lightweight design of high-speed train lead to intensified elastic vibration of the major components of the vehicle system.High-frequency elastic vibration can cause many problems. Such as, carbody floor chattering deteriorates the rides comfort; Bogie frame high frequency vibration causes structural fatigue damage; Wheelset high frequency vibration brings noise pollution and uneven wear. The multi-body system dynamics theory was adopt and rigid-flexible coupling dynamic model of vehicle systems are established to study the interaction between elastic vibration characteristics of structural and the vehicle dynamic performance. Rig id-flexible coupling simulation mainly depends on common multi-body dynamics software at present. But for special simulation requirement, such as structural dynamic stress calculation, elastic wheelset simulation, the implement process is more complicated, and even impossible to achieve. Therefore, this paper focus on rigid-flexible coupling theory study and vehicle dynamics and their related technologies research to build rigid-flexible coupling simulation platform of vehicle system. The following aspects are studied:(1) Rigid-flexible coupling dynamics theory of general multi-body system is studied in detail. And on this basis, the trajectory coordinate system was introduced to derived rigid-flexible coupling dynamic formulations of vehicle system. The train modeling method based on the vehicle substructure was investigated.(2) On the basis of contact line method, segments contact points search algorithm was developed for multiple points contact situation. In order to ensure the stability of the simulation, wheel-rail contact geometry correction and multilayer smoothing method were used to get smooth wheel-rail contact parameters.(3) A general multi-rigid-body dynamics simulation platform with flexible body pre-processing module, rigid-flexible coupling module and wheel-rail contact module formed a rigid-flexible coupling dynamic simulation platform of vehicle system. Established Rigid body dynamics model of vehicle system, rigid-flexible coupling model of general multi-body system and rigid-flexible coupling model of vehicle system and designed several cases to validate the platform. The results certificate the accuracy and reliability of the platform.(4) Rigid-flexible coupling of wheelset described by Lagrangian method and programming difficulties caused by wheelset large angle rotation was studied. In order to solve those difficulties, new equations based on Arbitrary Lagrangian-Eulerian (ALE) method were derived, and wheel-rail contact point calculation method of flexible wheelset was designed.(5) Rigid-flexible dynamic model of vehicle system considering the elastic deformation of carbody, bogie frame and wheelset were built on the dynamic platform. The elastic deformation characteristics and its influence on vehicle dynamic were analyzed. |
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