Dynamic Analysis And Equivalent Circuit Simulation Of Three Piece Bogie

Heavy load and speed increase of railway freight transportation have always been the goals pursued by China’s railway departments.Due to its outstanding advantages of simple structure,convenient maintenance,and strong bearing capacity,the three-piece bogie has become the most widely used freight truck bogie in China through upgrading and transformation over the years.This paper takes Zhuan K6 bogie as the research object and completes the following work:After carrying out force analysis on key components of the bogie,a differential equation of the bogie motion was established.Due to the numerous nonlinear factors of the three large pieces of the bogie,the relative motion and interaction forces between the components are more complex,so it is necessary to further analyze the nonlinear factors in the interior of the bogie before establishing a dynamic model.The effect of the friction damper secondary stiffness bolster spring under empty and heavy vehicle conditions was analyzed,The friction forces between the main and auxiliary friction surfaces of the friction damper wedge during loading and unloading are calculated;The hysteresis characteristics of viscoelastic materials are analyzed from the perspective of constitutive equations,and the relationship between the periodic energy consumption and the excitation frequency of the Kelvin model and Maxwell model is compared.The elastic rubber pad is simplified to a Kelvin model that is more suitable for describing the viscoelastic properties of rubber materials;According to the joint bearing mode of the center plate and side bearing of the Zhuan K6 bogie,and in combination with the technical requirements for the rotational torque of the freight car under empty and loaded conditions,the minimum value of the friction coefficient of the center plate surface is calculated.Based on theoretical analysis,a multi body dynamic model of a three piece bogie is established using UM software.During the modeling process,the nonlinear factors inside the bogie are considered.According to theoretical analysis,the interaction forces between various components of the bogie are simulated using force elements that conform to engineering practice,making the modeling more reasonable and reliable;Based on literature and engineering practice,the lateral and longitudinal stiffness of rubber pads and the stiffness of cross bracing rods were optimized;The critical speeds of vehicles with and without cross support devices are calculated;Based on the current Chinese standard GB/T 5599-2019 "Specification for Evaluation and Test Evaluation of Dynamic Performance of Rolling Stock",this paper analyzes the operational stability,smoothness,and quality of vehicles under different conditions of straight and curved lines,empty and loaded vehicles,and conducts a comprehensive and systematic evaluation of the vehicle’s dynamic performance.Based on the reasonable evaluation of vehicle dynamics performance,the equivalent circuit method is introduced into the study of vehicle system dynamics.The feasibility of equivalent circuit models was theoretically analyzed,and the equivalent processes of the two models were derived;Taking the lateral vibration model of the bolster as an example,numerical simulation and circuit simulation were conducted on the dynamic model,and the results of the two simulation methods were consistent,verifying the feasibility of the equivalent circuit model;A two degree of freedom dynamic model of wheelset lateral movement and shaking head with clearance in the axle box was established,and the effect of nonlinear axle box stop contact force on wheelset lateral movement and shaking head movement was studied using equivalent circuit method;A vertical vibration circuit model of the vehicle was established,and the vertical stability of the vehicle under empty and heavy vehicle conditions was analyzed.