Failure Mode Analysis And Life Prediction Of Rigid Droppers For Overhead Catenary

Droppers are important components in overhead contact networks.With the widespread application of rigid droppers,in order to reduce the impact of rigid dropper failures on the bownet system,improve the safety of train operation,and reduce property damage,more attention must be paid to the life of rigid droppers.The life of rigid suspension strings needs to be paid attention to by designers,builders and operators.Predicting the life of rigid droppers can be used to help estimate the overall life of the catenary,and it is helpful to improve the reliability of the catenary using the rigid dropper.In this paper,the rigid dropper is taken as the research object.The theoretical analysis,bownet simulation and vibration test are used to study the failure mode of the rigid dropper and to estimate its life.First,a basic introduction to the overhead catenary system and the structure of the rigid dropper is introduced.The applicable environment of the rigid dropper and its advantages and disadvantages are analyzed.The three failure modes of the rigid dropper are analyzed: fatigue fracture,shedding of rigid droppers and abnormal wear of insulation sleeves.It is found that several failure modes of the rigid dropper are related to its vibration.Secondly,the finite element method is introduced.The simplified model of pantograph,simplified model of overhead catenary and coupled model of pantograph and catenary are established.The pantograph simulation is carried out with the pantograph and overhead catenary of Lan-Xin highspeed railway as the model,and the dropper simulation results of force change curve,bearing cable displacement curve and contact line displacement curve.In terms of testing,by querying various standards,the establishment standards of the rigid dropper test bench were established,and a test bench composed of a vibration system,a measurement system and a control system was established,and various parameters of the test were determined,including the length of the rigid dropper,Test load,string strength,motion amplitude of rigid string,motion curve,test frequency,etc.Finally,the experimental steps of the rigid dropper vibration test were determined in order: sensor calibration,task setting,test data recording and analysis of experimental results.The effects of dropper force,amplitude,and length on the life of the rigid dropper were studied through experiments.Through the analysis of the test results,two main conclusions are obtained: under the condition that the rigid dropper has the same length,amplitude,and frequency,the larger the dropper force,the shorter the life;when the rigid dropper length,suspension force,and frequency are the same,the amplitude the larger,the longer the life.