Train Dynamic Response Analysis Of Rail Surface Deformation In Arch Section Of High-speed Railway Subgrade

With the rapid development of high-speed railway,the requirements of safety,stability and comfort of train operation are also improved.In the construction and operation of high-speed railway,new problems of coupling with environment inevitably arise because of the speed increase.Especially in the northern region,because of the existence of micro-expansive mudstone in the foundation,the swelling effect occurs when water meets,resulting in the arch disease of the second double-track Subgrade in Lanxin,which seriously affects the safety and stability of train operation.Based on SIMPACK and ANSYS,a multi-body dynamics simulation software,the track elevation of the upper arch section is measured.The vehicle-line coupling analysis of track curve fitting and track irregularity is carried out,and the dynamic response of the track irregularity of the upper arch section of the train is carried out based on the safety and stability indexes.The relationship between the amplitude,wavelength and velocity of the arch should be analyzed.The main contents of this paper are as follows:(1)Using SIMPACK simulation software,a multi-body dynamic simulation model is established based on the sub-structure fast modeling method.With the help of ANSYS finite element analysis software,the structure of CRTS I double-block ballastless track is modeled and analyzed.By substructure analysis,the finite element model is introduced into the dynamic simulation model to form the rigid-flexible coupling model of vehicle-rail system for dynamic response analysis.(2)According to the magnitude of the upper arch,the abnormal elevation data of the upper arch section of the subgrade are processed into track irregularity and line alignment respectively,and the SIMPACK model is introduced for dynamic simulation.The vertical and transverse dynamic indices of the vehicles under different speeds are analyzed and compared with the measured data,and then the rail surface deformation analysis method and the train dynamic response law under different arch amplitudes are determined.(3)The single-point arch of subgrade is simulated by circular curve,sinusoidal curve and parabolic curve,and the track irregularity is introduced.Then the influence of different arch amplitudes on the dynamic performance of trains under three kinds of curve simulation is analyzed,and compared with the measured values on the spot,the better curve is selected to simulate the track irregularity caused by single-point arch of subgrade.From the analysis results,it can be seen that the difference between the three curves is small,but the dynamic response value under the parabolic curve simulation is safer,so the parabolic curve is chosen.(4)When the upper arch amplitude is less than 30 mm,the track irregularity is simulated based on the parabolic curve,and the influence of different velocity and the upper arch amplitude on the safety and stability of train dynamic response is analyzed by introducing the model.When the upper arch amplitude is greater than 30 mm,the influence of the large upperarch amplitude and velocity on the vertical dynamic response of the train is analyzed based on linear reconstruction.The results show that with the increase of speed and amplitude under track irregularity simulation,the vertical dynamic response index of train increases,and the influence trend of amplitude increases linearly,which is far greater than that of speed.Under the linear reconstruction simulation,the vertical dynamic index increases with the increase of velocity,and the amplitude has little effect.(5)Based on parabolic curve,the influence of track irregularity wavelength on train vertical dynamic index is analyzed.With the increase of the wavelength,the vertical dynamic index of the train decreases.