Research On The Influence Of Flexible Structure On The Dynamics Of Rail Vehicles

With the rapid development of China’s high-speed railways,the speed of trains has been greatly improved,so higher requirements for vehicle system dynamics have also been put forward.The previous multi-rigid body dynamics calculation method ignored the elastic deformation of the vehicle structure,or only regarded one of the wheelset,frame,and track as a flexible body,which no longer met actual needs.In order to obtain more scientific and accurate dynamics data and ensure the safety,stability and comfort of vehicles at high speeds,it is necessary to carry out research on the influence of multiple flexible structures on vehicle dynamics.Based on the theory of multi-rigid body dynamics and the basic principles of rigid-flexible coupling dynamics,this paper takes a high-speed passenger car as the research object,considers the wheelset,frame and track as flexible bodies,and uses finite element analysis software ABAQUS and multi-body dynamics software SIMPACK.Study the dynamic response of the vehicle system under multiple flexible bodies.The specific work is as follows:(1)First,establish a multi-rigid vehicle model based on the dynamic parameters of a certain type of high-speed passenger car,and consider the nonlinear characteristics of part of the bogie damping device,such as the damping of the anti-snake shock absorber and the primary vertical shock absorber.(2)Then the three-dimensional solid model of wheelset,frame and track is analyzed in finite element software ABAQUS for modal analysis and substructure analysis,and the file is imported into SIMPACK through FEMBS interface program to obtain the flexibility of wheelset,frame and track Body file.(3)Establish vehicle rigid-flexible coupling dynamics model considering bogie flexibility,vehicle rigid-flexible coupling dynamics model considering track flexibility,and vehicle rigid-flexible coupling dynamics model considering both bogie flexibility and track flexibility.(4)Finally,calculate the serpentine motion stability,vehicle running safety,and vehicle running stability of the above four vehicle models,compare and analyze the settlement results of the four vehicle models,and analyze the effect of multiple flexible structures on vehicle dynamics Specific impact on performance.The results show that both the bogie and track flexibility will reduce the non-linear critical speed of the vehicle’s serpentine motion,and as the number of flexible structures increases,the greater the decrease;the multi-flexible structure makes the vehicle system’s derailment coefficient,wheel-rail(axle)lateral The force is obviously increased,and with the more flexible structure,the greater the increase,the wheel load reduction rate also shows this law;the multi-flexible structure increases the lateral stability of the vehicle,but reduces the vertical stability of the vehicle.The low-speed conditions have a greater impact on the vertical stability,and the high-speed conditions have a greater impact on the lateral stability.