Research On Influences Of High-speed Train Curve Passing Performance With Wheelset Flexibility

The factors of high speed and lightweight design of high-speed train intensify the elastic vibration of the main structural components of the vehicle system.The elastic vibration of high frequency will cause the wheel-rail abrasion,the wheel-rail noise increase,non-circular of wheels,the vehicle comfort and the safety decrease.Therefore,the influences of the flexible characteristics of the main structural components of the vehicle system on the dynamic performance of the vehicle system can’t be neglected because the material is generally flexible,it will be more realistic if it is considered as flexible.In this thesis,the trailer wheelset of CRH2 is considered as flexible body,and the influence on the dynamic performance of vehicle curve passing is studied,and the results are compared with the calculation results of the vehicle dynamic model of multi-rigid body system.Firstly,based on the multi-body system dynamics analysis software SIMPACK,the dynamic model of multi-body vehicle based on the dynamic parameters of CRH2 trailer vehicle.Secondly,using the SolidWorks to model the trailer wheelset of CRH2,and mesh it in the HyperMesh,and the finite element model of wheelset are imported into ANSYS to analyze its substructure and modal.The quality,stiffness and damping matrices,the natural frequencies and modal modes of wheelset are extracted by substructure analysis and modal analysis respectively.Finally,the extracted flexible wheel information is input to SIMPACK to generate flexible wheelset model and dynamic model of rigid-flexible coupling vehicle.The dynamic response of the two models under different curves is analyzed,and the performance of the vehicle curve passing is studied under the stimulation low disturbance spectra of German,.The calculation results show that the car body acceleration and Sperling index of the flexible model are both slightly larger than that of the rigid one.After consideration of the flexible wheelset.The flexible wheelset has less influence on the running smoothness of the vehicle;The increase of wheel-rail lateral force,the wheel-axle transverse force and the derailment coefficient increase obvious on the curves,which influences on the wheel rail vertical force and the wheel load reduction rate is small.By the dynamic model of vehicle rigid-flexible coupling system,the influence of curve radius,super-elevation,easement curve length and rail bottom slope on the performance of vehicle curve passing is studied.The results show that the proper increase of curve radius can reduce lateral acceleration,transverse Sperling index,wheel axle transverse force,wheel load reduction rate,and wheel rail vertical force,wheel rail lateral force,derailment coefficient of the outside wheel.The excessive radius of the curve has not obvious influence to the improvement of the vehicle dynamics performance.When the balanced super-elevation is 70 mm and set the super-elevation is 90 mm,that is,the vehicle is in a small surplus super-elevation state,running smoothness and security of the vehicle a re better.Proper increase the length of the smoothing curve can effectively reduce the wheel load reduction rate,but the effect on other dynamic performance indexes is less.Proper adjustment of rail bottom slope to the vehicle running smoothness and security is small,comprehensive consideration of the changes in the dynamics of indicators,when the bottom slope of the axle is 1/40,the vehicle running smoothness and security are better.