| With the rapid development of high-speed railway in China,the running speed of train has been greatly improved,which greatly enhances the interaction between wheel and rail.As the main excitation source,track irregularity affects the dynamic response of vehicle track coupling system.Therefore,it is of great significance to study the dynamic response of vehicle track spatial coupling system under the excitation of track irregularity for ensuring the safety and stability of railway vehicle operation and formulating track maintenance strategy.Based on the principle of vehicle track system coupling dynamics,a vehicle track spatial coupling dynamic model is established,and the random track irregularity is taken as the input excitation of the coupling model.The dynamic response of vehicle track space coupling system is obtained by using SIMPACK dynamic analysis software and ABAQUS finite element analysis software,and the dynamic response of vehicle components and track under different working conditions is simulated.At the same time,the time-frequency analysis technology is used to analyze and compare them.In this thesis,the vehicle track space coupling dynamic model is established firstly,and the vibration equations of vehicle and track are derived in detail according to D’Alembert principle.This thesis introduces the classification of track irregularity excitation,and simulates track irregularity in time domain based on power spectral density function.In this thesis,SIMPACK dynamics software is used to complete the establishment of vehicle model,including: wheelset,bogie,car body three models.Because the default rail in SIMPACK is rigid rail,which does not meet the actual needs,this thesis uses ABAQUS finite element analysis software to design the flexible rail and import it into SIMPACK for CO simulation.In SIMPACK,based on the track irregularity spectrum,the simulation of high-low,horizontal and composite track irregularity excitation is realized,and added to the whole system as system excitation.Then,based on the joint modeling of SIMPACK and ABAQUS,the dynamic responses of vehicle track system under the action of high-low irregularity,directional irregularity and composite irregularity are simulated.The acceleration of vehicle body components,rail vibration acceleration and wheel rail force in time domain are compared and analyzed,and the time-frequency analysis in frequency domain is carried out based on FFT and STFT.At the same time,the comparative analysis under different conditions is carried out,including the response comparison under different types of irregularity,different speeds,different amplitude of irregularity,different line grades and different vehicle types.Through simulation and comparative analysis,the results show that in the dynamic response of vehicle track coupling system,the influence of direction irregularity on lateral dynamic response is greater than that on vertical dynamic response;Due to the damping effect of the suspension system,the higher the vehicle system components are,the smaller the vibration is;According to the frequency domain analysis of the dynamic response of the vehicle rail system,the wheel rail force is concentrated in the low frequency band of0 ～ 40 Hz,and the acceleration of vehicle components is concentrated in the low frequency band of 0 ～ 20Hz;With the increase of vehicle running speed or the amplitude of irregularity,the dynamic response of vehicle track system is obviously enhanced;Under the condition of this model,the response of us spectrum is 20 ～ 50% higher than that of China spectrum in vertical direction and 50 ～ 80% higher in horizontal direction;Under the same track spectrum,the vibration acceleration of vehicle components of CRH2 bus is 5 ～ 30% higher than that of CRH3 bus,and the vibration acceleration of track is 15%higher than that of CRH3 bus.The influence of wheel rail vertical force is not obvious,which increases by 3%,but the wheel rail lateral force increases by 33%. |
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