Study On Stiffness Distribution Of Catenary And Pantograph-catenary Contact Force Based On New Droppers

At present,the high-speed pantograph-catenary relationship has become one of the important factors restricting the development of high-speed railway technology.The pantograph-catenary relationship directly affects the current collection quality of pantograph-catenary.The droppers are an important structural component of catenary.This thesis studies the influence of droppers on the performance index of pantograph-catenary current collection by using the finite element simulation software.Firstly,based on the catenary of Beijing-Tianjin Intercity Railway,Beijing-Shanghai High-speed Railway and the CX-NG pantograph,catenary-pantograph models of simple chain catenary and elastic chain catenary are established by MSC.Marc software.Secondly,this thesis studies the influence of line density and Young's modulus of droppers for stiffness distribution of catenary by analyzing the stiffness curve of catenary and the stiffness curvature of droppers spacing in MATLAB.By analyzing the curve of contact force and the changing trend of contact force,this thesis studies the influence of linear density and Young s modulus of droppers for pantograph-catenary contact force.It shows that reduction of the linear density and Young's modulus of droppers can reduce the maximum stiffness of the catenary and the stiffness change rate within the droppers spacing,and make the stiffness distribution of the contact more uniform.For contact force,it can reduce the steepness,dispersion and variation scope of contact force.Therefore,the lightweight and low modulus of droppers can improve the current collection quality of pantograph-catenary.At the same time,this thesis studies the influence of failure of droppers for the current collection quality of pantograph-catenary.The failure of droppers at different locations of catenary can deteriorate the current collecting quality of pantograph-catenary,and the failure of droppers in the middle of span has little effect on the current collecting quality.Finally,according to the series standards of catenary components for electrified railway,aiming at lightweight and low modulus of droppers,and taking into account the breakdown of droppers,Kevlar29 is selected as the material of new droppers.In order to analyze the influence of new droppers for the current collection quality of pantograph-catenary,the pantograph-catenary relationship model of new droppers is established in MSC.Marc software.From the results,the new droppers can make the stiffness distribution of catenary more uniform.The new droppers can improve the change of contact force and reduce the off-line rate of pantograph-catenary under different speed conditions.After using the new droppers,the improvement of contact force of simple chain catenary is obviously better than that of elastic chain catenary,and with the increase of speed,the improvement of contact force of simple chain catenary is more obvious.After using the new droppers in the catenary,the deterioration of current collection quality of pantograph-catenary has been improved when dropper fails at different positions.It is proved that the new droppers of Kevlar29 can improve the current collection quality of pantograph-catenary,and the excellent physical,mechanical and chemical properties of Kevlar29 can reduce the occurrence of droppers fracture.71 images,28 tables,64 references...