Development Of Train Collision Dynamics Simulation Platform And The Influence Of Coupler System Parameters On Collision Performance

Passive safety of trains is an important part of vehicle design.In the initial stage of design,it is difficult to use the finite element simulation method to verify the rationality of the train’s crashworthiness design quickly.Due to the strong nonlinear factors in train collision process,the traditional dynamics simulation software cannot simulate its characteristics accurately.Coupler and draft gear are contacted first and have a great impact on the subsequent collision behavior of train.Therefore,the thesis established a train collision dynamics model to study the impact of the parameters of coupler and draft gear on the train collision,and built a simulation platform for train collision dynamics.The finite element method was used to verify the calculation accuracy of the platform.Based on the EN15227 rail vehicle collision standard,The state of coupler and draft gear is studied on the longitudinal and vertical response of the train,and the correlation between coupler and draft gear and other vehicle parameters is compared.The results provide a certain degree for the selection of vehicle parameters such as coupler and draft gear in the crashworthiness design of rail vehicles.Guidance methods help improve the passive safety of trains.First of all,based on the typical vehicle-track coupling dynamics model,the vehicle and track mechanics equations are derived,the vehicle model and the track model are established.The loading and unloading of coupler and draft gear is established based on the "look-up table method" and "partial transition method" mathematical model.The three-dimensional transfer function of the coupler force between the coupler and the car body is derived,the nonlinear contact model between the wheel and the rail,the model of the energy-absorbing anti-climbing device and the model of the suspension device are established to form a complete train collision dynamics model.At the same time,a finite element model of a certain type of four-group rail vehicle is established.Model is calculated in the LS-DYNA solver,and the vehicle parameters are extracted and substituted into the train collision dynamics parameterized model for dynamic calculation.The collision responses such as vehicle speed,vehicle acceleration,and wheel set lift are selected for comparison and verification.The results show that the change trend of the results of two calculation model is the same,which verifies the accuracy of the train collision dynamics model.Then,based on the Visual Studio MFC program framework,the MATLAB calculation engine is used as the solver,and the VTK visualization library is used as the post-processor.The transfer function of different data types between the main program,solver and post-processing is designed.The technical route of calculation results from the solver to the visualization postprocessing module is realized,and a program hybrid architecture suitable for parameter reading and writing,solution calculation and visualization is constructed,and a data transfer between the main program,the solver,and the pre-processor and post-processor is explored.The mixed programming route builds a simulation platform for train collision dynamics.On this basis,the force value and stroke parameters of coupler and draft gear are selected,and the parameter changes of the crush tube and the buffer are used to study the overall collision response of the train,and the most influential state parameters are screened out to study the correlation with other vehicle key parameters.Finally,the research results show that: the force level of the crushing tube of the leading car coupler has a major influence on the vehicle collision response,and during the increase of the force level,there exist a sudden increase in the maximum wheelset lift.The stroke of the middle coupler buffer will have a greater impact on the vehicle collision response,and its stroke has a stable negative correlation trend with the maximum wheelset lift.In the analysis of the correlation between the parameters of coupler and draft gear and the vehicle parameters,the secondary vertical stiffness,the length between truck pivot centers and the nodding inertia of the vehicle body all have the highest correlation in different stages of numerical changes.