Research On Bogie Dynamics Based On Rigid-flex Coupling Model

In recent years,the rapid development of high-speed railway technology in China,especially the smooth operation of the Chinese standard EMU Fuxing,has greatly improved the travel experience of the people.As the train speed increases and the operating environment becomes more complex,the traditional multi-rigid-body dynamic design is concerned by vehicle designers because it does not consider the changes in train dynamics caused by the elastic deformation of the vehicle structure.In order to obtain more rigorous and accurate dynamic results in the vehicle design stage,and to ensure safe high-speed driving and excellent stability of the EMU,it is necessary to conduct a study on the specific effects of rigid-flexible coupling on vehicle dynamics.This article first explains the source and significance of the subject,and introduces the relevant basic principles of vehicle rigid-flexible coupling dynamics and the research methods and ideas of this article.Then introduced the three major dynamics evaluation indicators of rail vehicles,as well as the evaluation standards formulated at home and abroad for the above dynamics indicators.Then,two models of multi-rigid body and rigid-flexible coupling were established respectively.Finally,the differences between the dynamic indexes of the multi-rigid-body model and the rigid-flexible coupling model in the same simulation environment are compared,and the effects of rigid-flexible coupling on vehicle dynamic performance are analyzed.The specific work is as follows:(1)Based on a certain type of high-speed EMU trailer dynamics parameter table,a fully rigid vehicle model is constructed,and the nonlinear characteristics of the partial suspension device of the bogie,such as the damping of anti-snake dampers and a series of vertical dampers;(2)The wheelset and framed solid models are flexibly processed in the finite element software Abaqus,including modal analysis and substructure analysis,and the flexible body is imported into Simpack through the FEMBS interface program;(3)Build three rigid-flexible coupled vehicle models with only wheelset flexibility,only frame flexibility,and wheelset and frame flexibility,and set up the same simulation environment as the full rigid vehicle model to calculate the snake motion stability of the above four vehicle models,Curve passing dynamic indicators such as safety and vehicle running stability;(4)Compare and analyze the settlement results of the four vehicle models,and analyze the specific impact of the flexibility of the steering frame structure on the vehicle dynamics performance.The results show that both the wheelset and the flexibility of the frame will reduce the nonlinear critical speed of the serpentine motion of the vehicle,and as the number of flexible structures of the bogie increases,the decrease will be greater;The lateral force of the wheel rail(axle)slightly reduces the wheel load reduction rate;the flexibility of the bogie structure will reduce the lateral and vertical stability of the vehicle.Among them,the low-speed operating conditions have a greater impact on the vertical stability.Under the circumstances,it has a greater impact on lateral stability;the wheel wear of the flexible wheelset Elkins index has a clear upward trend with the increase of vehicle speed,while the rigid wheelset does not change significantly.