Structural Optimization And Performance Analysis Of Elastic Backing Plate Under Railway Track

The under-rail elastic pad is an important elastic component of the track fastener system.Its main function is to provide elasticity to the track and to cushion the wheel-rail interaction generated when the train passes.For the ballastless track,the elasticity of the track system is all provided by the elastic plate of the fastener,so it is extremely important to optimize the structure of the elastic pad under the rail and improve its performance.The finite element analysis software was used to optimize the under-trending hexagonal mesh rubber elastic pad in the fastener system,and the displacement-load response curve and internal stress distribution of different mesh inner diameter and mesh spacing pads were calculated.The static stiffness,dynamic stiffness and dynamic and static stiffness ratio of the elastic pad were calculated by the relevant test methods.The variation of the stiffness characteristics of the pad with the mesh size of the pad was analyzed.The filling of the high damping packing block to the mesh pad was studied.The influence of stiffness and damping characteristics is compared.The mechanical properties of mesh-type elastic pad and traditional grooved elastic pad are compared.The vehicle-orbit dynamics model is used to study the elastic-pad-to-vehicle-track system of different structures.The effect of dynamic performance.The results show that the static stiffness of the regular hexagonal mesh pad is proportional to the mesh spacing,and the increase decreases with the increase of the mesh spacing.The static stiffness of the mesh pad and the inner diameter of the mesh are The inverse ratio,and the decrease decreases as the inner diameter of the mesh increases.According to this rule,the static stiffness value of the mesh pad can be controlled by adjusting the structure.The dynamic and static stiffness ratio of the mesh pad decreases as the spacing between the meshes increases,and increases as the inner diameter of the mesh increases.The internal stress of the mesh pad is mainly distributed in the intersection of the internal structural faces of the mesh.When the hole spacing is too different from the inner diameter of the mesh,the stress distribution is uneven inside the pad.Therefore,the mesh pad structure is designed.It is not advisable to adopt a structure in which the inner diameter of the mesh and the hole pitch are too large.The comparison with the grooved pad shows that the mesh-type elastic pad has less static stiffness,smaller dynamic and static stiffness,more uniform internal stress distribution,and the maximum Mises stress of the mesh-type elastic pad can be reduced by 26.9%.And the material is saved by 20%.Filling the mesh structure with high damping material can improve the damping performance of the mesh type elastic pad and adjust the displacement of the fastener system to achieve the secondary static stiffness.In the process of compression,the mesh pad withhigh damping material is not changed when the distance between the pad and the upper and lower surfaces of the pad is greater than 0 mm.When the pitch is compressed to 0 mm,the static stiffness of the pad is sharp.Increase,the second static stiffness occurs.The mesh pad filled with high damping material can greatly increase the damping ratio of the pad(much higher than the grooved pad),and effectively reduce the internal stress intensity of the pad and improve the stress distribution inside the pad.The life of the pad is extended.Based on the research results of the vehicle-rail system theory,it can be seen that improving the damping parameters of the elastic pad under the rail can effectively reduce the vertical force of the wheel and rail,the vertical displacement of the rail,and the vertical acceleration of the rail.Compared with the grooved pad,the mesh pad filled with high damping material can reduce the vertical force of the rail by 31.8%.Due to the reduction of the wheel-rail force,the impact between the wheel and rail is weakened,thereby alleviating the wear between the wheel and the rail;reducing the displacement and acceleration of the rail relieves the vibration response of the rail,and effectively protects the under-rail foundation structure,so the filling is used.The high-damping material mesh pad has a very positive effect on reducing wheel-rail interaction force and rail vibration.