Study On Vibration Reducing Characteristics Of CRTSⅢ Slab Ballastless Track Of High-speed Railway

With the rapid development of high-speed railway in China,CRTS-III slab ballastless track with independent intellectual property rights has become one of the main tracks in the construction of high-speed railway.In order to solve the increasingly prominent problem of wheel-rail vibration and the noise problems encountered in the implementation of the strategy of"going out"for high-speed railway in China,it is of great practical significance to study the vibration reduction characteristics of CRTS-III slab ballastless track.Based on the three-dimensional beam-body track model and vehicle-track-subgrade vertical coupling model are established respectively.Then,the finite element software ANSYS and multi-rigid-body dynamics software UM are used to analyze the vibration response caused by the change of track structure parameters.Specific research contents are as follows:Firstly,according to the parameters of CRTS-III slab ballastless track of high-speed railway,a three-dimensional beam-body track structure model is established in ANSYS by choosing appropriate finite element elements and interlayer connection elements.By comparing the modal results of track slab models with different lengths,18 models of track slab lengths were selected and the natural frequencies and modes of track models were analyzed.The effects of the thickness of fasteners,supporting layer,top layer of foundation bed,bottom elastic modulus and foundation elastic modulus on the natural frequencies of track system are analyzed.The results show that the stiffness of fasteners and the elastic modulus of the damping layer have little influence on the natural frequency,while the thickness of the supporting layer and the elastic modulus of the top and bottom of the bed have great influence on the natural frequency.Secondly,the UM software and ANSYS-UM interaction steps are introduced.A multi-rigid vehicle model and a flexible track model are established.The model is imported into UM software.The vehicle-track-subgrade model is established and the model is verified to be correct.Finally,The vehicle-track-roadbed coupling model is simulated and analyzed in UM.The function of structure parameters on the dynamic response of vehicle-track-roadbed system is studied from the angle of vehicle safety and optimization of track performance.The results show that when the fastener stiffness is 40 kN·mm^-180kN·mm^-1and the damping stiffness is 30 MPa·m^-1100 MPa·m^-1,the vibration response is without effect.The elastic modulus of the top layer of the foundation bed should be greater than 120 MPa.Increasing the elastic modulus of the top layer of the foundation bed can reduce the dynamic response of the coupling system,which provides a reference for the popularization and application of CRTS-III slab ballastless track.