Modeling Of Friction And Analysis Of Frictional Vibration Of Pantograph-catenary Under Fluctuation Load

The pantograph and the catenary are two independent elastic systems.When the train is running at high speed,the contact portion of the pantograph slide and the contact line generates waves due to vibration.The waves will occur when they meet the suspension string and the positioner.Refraction and reflection make the contact force loaded between the pantograph slide plate and the contact line present a fluctuating nature.The pantograph skateboard obtains electrical energy from the grid through sliding contact with the contact line.The two slide through each other while passing a certain current.At the same time,there are mechanical wear and electrical wear,and friction is an important cause of pantograph wear.Factors,it is of great significance to study the friction of the Pantograph-catenary.In order to model the Pantograph-catenary friction force,the relationship between friction force and pressure fluctuation frequency,pressure fluctuation amplitude,contact current,and sliding speed were studied using a laboratory-made high-performance current-carrying friction and wear testing machine.The results showed that: sliding The friction force does not change significantly with the pressure fluctuation frequency;the friction force increases with the pressure fluctuation amplitude,and the two are approximately linear;the friction force gradually decreases with the increase of the contact current,and the two are also approximately linear;The frictional force increases with the increase of the sliding speed.The two are no longer in a linear relationship,but show an obvious nonlinear relationship.According to the above research results,a static model of the Pantograph-catenary friction force is established,and the parameters in the model are identified by using the Macquart method and the general global optimization method.Based on the established static model of the Pantograph-catenary friction force,the paper introduces Dynamic parameters,the dynamic model of the friction force of the Pantograph-catenary is established,and the dynamic parameters in the model are identified by the genetic algorithm combined with Simulink simulation;finally,the measured values and the output values of the two models and the pure mechanical friction model are output Comparison of the values,the results prove that the dynamic model is more effective,and further analysis of the mechanism of the impact of the pantograph friction and the superiority and universality of the dynamic model,this is the prediction of the friction force of the pantograph and the study of the friction and wear performance for reference.By studying the effects of pressure fluctuation frequency,fluctuation amplitude,contact current,and sliding speed on the acceleration of the pantograph current-carrying frictional vibration,the results show that the vibration acceleration does not change significantly with the pressure fluctuation frequency;the vibration acceleration increases linearly with the increase of the pressure fluctuation amplitude;Vibration acceleration gradually decreases with the increase of contact current;Vibration acceleration increases with the increase of sliding speed,and its change trend is more obvious than the trend of vibration acceleration with pressure fluctuation amplitude.The above relationships all exhibit a linear relationship.In this thesis,the research of friction force modeling and the analysis of the acceleration characteristics of the current-carrying frictional vibration of the pantograph have further enriched the relevant research on the sliding electrical contact of the pantograph,and laid the foundation for the subsequent research on friction dynamics.