Research On Collision Performance Of Urban Rail Train Based On Rigid-flexible Coupling Model

With the rapid development of urban rail transit in China and the continuous improvement of train speed,people pay more and more attention to the safety of urban rail trains.It is particularly important to study the passive safety protection technology in the design process of rail trains.Based on the research methods and achievements of passive safety protection technology for urban rail vehicles at home and abroad,the crash performance of urban rail vehicles is studied by multi-body dynamics method.Based on the requirements of EN15227-2011 standard and related technical conditions,this paper defines the scene of multi-body collision of urban rail trains,and puts forward the technical route of one-dimensional rigid-body collision and rigid-flexible coupling collision simulation.Based on the software platform of MATLAB/Simulink,the coupler force element control program expressing the mechanical characteristics of coupler and energy absorption structure is compiled.Based on the UM software platform,the dynamic model of continuous collision of eight-marshalling urban rail train is established.The coupler force element control program is imported into UM to realize the joint simulation of UM and MATLAB/Simulink,and whether it can meet the requirements of connecting collision energy absorption under three speed conditions is analyzed.The correctness of the Simulink model of coupler force element is verified.Based on HyperMesh software platform,the finite element models of Mc,Tp and M car body of the urban rail train are established.The corresponding modal calculation is carried out based on ANSYS software platform.The flexible body models of each car body are established by running ANSYS_UM program.The flexible car body model is imported to replace the corresponding rigid car body,and the rigid-flexible coupling collision model is established.In order to study the impact of flexible car body on train collision process,three rigid-flexible coupling train collision models are designed,and their collision performance at 25 km/h speed is studied.Three rigid-flexible coupling train collision scenarios are formulated.Three rigid-flexible coupled train collision models are simulated in UM under 25 km/h speed.The simulation results show that the longitudinal collision impact is mitigated by the elastic deformation of the flexible body,resulting in the decrease of the longitudinal force at the collision interface and the peak acceleration of the vehicle.The energy absorption characteristics of the coupler at the collision interface of the flexible body change significantly.Compared with rigid body collision,the energy absorption value of the coupler of the replaced flexible car body increases,which indicates that the elastic deformation of the flexible car body in the continuous collision balances the energy absorption of the coupler at each interface.Finally,compared with the results of non-linear finite element collision analysis,the results of rigid-flexible coupling model are closer to the results of non-linear finite element collision than that of rigid body model.With the increase of the number of flexible body replacement,the interface energy absorption is closer to the results of non-linear finite element simulation,which verifies the accuracy of the rigid-flexible coupling model.