Study On Mechanical Characteristics Of High-speed Railway Catenary Cantilever System

The overhead catenary line has been playing a vital role in the vehicle energy supply of high-speed railways,which is characterized by its long-span and flexible structure.The working state of the cantilever of catenary is closely related to its stress condition.Catenary fluctuation will not only influence the vehicle current collection,but also the overhead structure's health state,leading to an increased failure rate of the catenary parts.Cantilever is an important part of the catenary structure,working as the support and locating device.The health state of the cantilever is closely related to the catenary vibration,as well known as the stress condition.The vibration loads transfer to the cantilever via the steady clamp,then cause the change of cantilever stress condition,which may lead to the fatigue crack and structural parts failures.Thus,it's necessary to study the dynamics features mechanical properties of catenary cantilever in different working conditions to improve its structural design.Firstly,the cantilever model is built based on the finite element method(FEM)with some adapting pieces taken into consideration.Then the cantilever properties of kinematics and statics under different working conditions are analyzed In the third part,the cantilever load features in different conditions are studied,including the icing condition and the static wind condition.The statics analysis results show that the maximum stress locates on the bolt position and the steady clamp which connecting the flat bracket and the oblique bracket,when considering the wind load and the ice load.And the maximum vertical displacement occurs on the clamp in the modal analysis,as the steady arm has higher risk of fatigue damage in the harmonic response analysis.Secondly,the cantilever dynamic model is established based on the hinge nonlinear model.And the loads transfer function and its distribution on the cantilever base are obtained via the mechanics equilibrium equations and the displacement equations,respectively.The results are also compared with the FEM simulation to verify its accuracy.The results of FEM calculation are basically in agreement with those of transfer function calculation the latter.Finally,the cantilever FEM model is validated in the dynamics test and the statics test,respectively.And the strain gauges are used to obtain the key data under the static force and the cyclic loading.The work in this paper provides a new way for the high-speed catenary cantilever design,simultaneously the modeling method used in the paper can be suitable for the FEM analysis of other cantilever types,which will benefit the investigation of cantilever dynamics.The simulation results in this paper are consistent with the experimental results and theoretical calculation results,and the research method is also applicable to the study of other types of cantilever.