Research On Dynamic Characteristics Of Stabilizing Device-ballast Track Coupled System For Dynamic Stabilizer

After cleaning and tamping operation on ballast,the railway would be poor stability and the state of the ballast bed can not meet the specified requirements,track dynamic stabilizer is a large railway operation and maintenance equipment to solve these problems.The research on the dynamic response characteristics of the stabilizer,rail row and ballast bed during the operation of the track dynamic stabilizer can provides theoretical foundation and data support for the structural transformation and intelligent operation upgrade of the track dynamic stabilizer.At the same time,it can provides references for the dynamic modeling and analysis of large railway operation and maintenance equipment such as ballast cleaning machinery and tamping vehicle.Based on the classic vehicle-track coupled dynamics theory,the purpose of this paper is to establish a set of stabilizing device-ballast track coupled dynamics model,which is suitable for the operation response analysis of track dynamic stabilizer,and to study the dynamic response characteristics of key parameters in dynamic stabilizing operation through this model.The main contents of this paper are as follows:The development overview of track dynamic stabilizer and vehicle-track coupled dynamics was introduced,the off-line test experiment of ballast bed state of actual railway was completed,and the physical model of dynamic stabilizing device-ballast track was established.According to the relevant railway industry standards,the state assessment standards and related indicators of the ballast bed were discussed,And the ballast bed state of the railway for on-line dynamic experiment was tested.The vertical stiffness and lateral resistance of the railway were obtained by fitting the test results of each measuring point.The structural principle of the track dynamic stabilizer and the stabilizing device was described.Based on the classic vehicle-track coupled dynamics theory,the coupled dynamics analysis model of stabilizing device-rail row-ballast bed was established.The simulation model of the coupled system was built,and the effectiveness of the simulation model was verified by comparing the field experimental data.The influence rules of different working conditions on the vibration response of the system were analyzed.Based on Hertz contact theory,the wheel-rail contact force was analyzed,and based on the physical analysis model,a virtual prototype simulation model of stabilizing device-rail row-ballast bed was built.The validity of the virtual prototype was verified by comparing the data of the online dynamic experiment and the simulation test of the track dynamic stabilizer.In the rigid rail environment,the frequency domain characteristics of the vibration response of the coupled system under five different track bed conditions were discussed,and the influence of vertical pressure on the dynamic response parameters was analyzed.The test results show:the resonance frequency points of the coupled system increase with the increase of the state parameters of the ballast bed,and the amplitude of the response parameters of the system is negatively correlated with the vertical pressure.Based on the flexible rail environment,the time domain characteristics of the dynamic response of each component of the coupled system and the influence range of lateral excitation were analyzed.A dynamic simulation model of the rigid-flexible coupled multibody system was established by using the modal superposition method to deal with the flexible rail.The time domain characteristics of the dynamic response of the stabilizing device,sleeper and ballast block under rigid and flexible rail environment were compareded and analyzed.By extracting the response curves of output points at different positions,the influence range of lateral excitation force on sleeper and ballast bed in the process of dynamic stability operation was compared and analyzed.The experimental results show:the excitation energy is mainly absorbed by the ballast bed in the process of dynamic stability operation.By comparing the positions of the output points from near to far,it is concluded that the amplitude attenuation law of sleeper and ballast bed block is basically the same.In the lateral acceleration,velocity and displacement responses,the amplitude variation law of each response parameter is basically the same,all of which are nonlinear changes.Between the output points No.2 and No.3,the amplitude attenuation speed of each response parameter of the sleeper and the ballast bed block is the largest.On both sides of this interval,the attenuation trend is relatively gentle.