| In order to avoid the inconvenience of urban traffic congestion to people’s lives and travel,most cities in China have built subways,and China has become the world’s largest urban rail transit market.The conductor rail system has been widely used in subways because of its advantages such as long service life,high reliability,and low maintenance costs.The currentcollecting equipment of the third rail train is consist of the electric shoe and the conductor rail.Electric energy is transferred between the electric shoegear and the conductor rail through sliding contact.The stable contact between the electric shoegear and the conductor rail is the guarantee for the reliable operation of the train.Contact force is an important indicator to evaluate the current collecting quality of electric shoegear and conductor rail.If the contact force is too large,the friction between electric shoegear and conductor rail will increase and the mechanical wear between electric shoegear and conductor rail will be accelerated;If the contact force is too small,the contact resistance between electric shoegear and conductor rail will increase and the power loss between electric shoegear and conductor rail.Therefore,it is of great significance to study the dynamic characteristics of electric shoegear and conductor rail.This article takes the electric shoegear-conductor rail system as the research object,establishes the finite element model of the electric shoegear-conductor rail system,and studies the influence of the train running speed,contact rail span,sliding shoe quality,support stiffness,contact stiffness and temperature on the shoegear-rail contact force.Providing theoretical support for the normal operation of the third rail system.Firstly,taking the electric shoegear and conductor rail system as the research object,according to the virtual displacement principle,the lumped mass model of the electric shoegear is derived.Based on the strain energy and kinetic energy equivalent principle,lumped mass model of the conductor rail support is obtained;Utilizing the method of penalty function,the accurate interaction model of shoegear-rail is developed considering the complex boundary conditions.The measured data of the Guangzhou Metro are used to verify the correctness and effectiveness of the finite element model of the electric shoegear-conductor rail system.In order to satisfy the technical requirements of the actual operation,the influences of electric shoegearconductor rail system parameters,such as train running speed,conductor rail span,sliding shoe quality,support stiffness and contact stiffness,on the contact force of the shoegear-rail are studied.The results provide theoretical support for improving the current collection quality of the shoegear-conductor rail system.Secondly,because the contact force is related to various factors such as the support structure,the height change of the positioning device and the running speed,the static and modal characteristics of the conductor rail are analyzed.The result shows: compared with the conductor rail arranged in equal spans,the deflection of the conductor rail arranged in unequal spans is more uniform,which is more conducive to the current collection.Finally,the effect of temperature change on the electric shoegear-conductor rail contact quality is studied.Based on finite element model of the electric shoegear-conductor rail system,considering the effect of different temperature values,the dynamic performance of the shoegearrail in different temperature fields is studied.Research results show: In the case where the insulating bracket is stuck,as the temperature of the conductor rail increases,the deflection of the conductor rail gradually increases.When the temperature change is greater than or equal to20 ℃,the reaction force of the bracket will destroy the insulating bracket.As the degree of destruction of the insulating bracket increases,contact quality of the shoegear-rail dynamic is also worse. |
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