Study The Influence Of Track Fasteners Installation By Structures And Materials

Rail fastener is an important part of connecting rail and sleeper,which plays an important role in ensuring the stability and reliability of rail.Fastener fatigue failure will cause damage to the track and vehicle structure parts,and even endanger the traffic safety.Therefore,it is necessary to study the mechanical properties of fastener system.Based on the elastic-plastic contact theory of finite element,the contact stress calculation and mechanical analysis of type II elastic bar fastener for passenger rail and type III elastic bar fastener for heavy haul rail are carried out in this paper.Finally,the optimal design scheme of the fastener is given.Firstly,this paper describes the composition of spring fastener system,and summarizes the research status of spring fastener at home and abroad.The boundary conditions and attribute parameters needed to establish the finite element models of type II and type III spring fastener are described in detail.Then,according to the field installation and use of the two kinds of elastic strips,a complete finite element model of the elastic strip fastener system is established by using the nonlinear contact theory.Secondly,it focuses on the analysis of different structures and materials of type II elastic strip fastener,studies and analyzes the variation law of equivalent contact stress and displacement under different arc radius at the contact between elastic strip and gauge baffle,so as to find the most suitable gauge baffle structure of type II elastic strip.The contact stress and its distribution on the surface of elastic strip under different structure and material conditions are analyzed to find and confirm the most suitable structure and material.Finally,the finite element analysis of type III elastic bar fastener system is carried out.When the elastic bar is installed in the correct way,that is,the length of the middle limb of the elastic bar inserted into the socket of the embedded iron seat is reasonable,the change law of the equivalent contact stress and displacement of the contact part of the elastic bar is analyzed.In order to find out the structural optimization scheme of the embedded iron seat at the contact of the middle limb of the type III elastic strip,and to explore the size and distribution of the contact stress on the surface of the elastic strip under different optimization schemes.