The Dynamic Parameter Optimization Technique Study Of The End Connection Structure On Vehicles

A railway vehicle is constructed by connecting multiple cars through car end connecting structures,which are one of the key components of a railway vehicle.A car end connecting structure is mainly consisted of coupler,windshield,passage,bumper,electric connector,crossing line connector,and braking connection and so on,of which the configuration and parameters have significant impact on the dynamic performance and the curve passing capability of railway vehicles,directly relating to security,stability and comfort,hence the study on testing system and testing technologies for dynamic parameters of car end structure is critical for the performance and reliability of railway vehicles.This thesis is in accordance with IEC standard,EN standard,UIC standard and GB standard etc,and based on six-DOF motion platform as well as flexible car end structure assembly.Simulations of vehicles passing through curves with various radii,such as Circular Curve,Straight Line-Curve,S Curve are conducted,and the motions of key parts in the car end connecting structure is studied to represent the attitude of the car end structure assembly,and to carry out studies on the dynamic performance parameter testing technology and motion coherence,hence optimizing the connecting structure parameters through analyzing the testing data.A testing system simulating actual working conditions of the car end connecting structure in a running train is deve lopped in this thesis.A dynamic parameter testing system and controlling software for car end connecting structure is also developped in this thesis.Static parameter tests of car end structure in various working conditions are conducted to provide theoretical evidence for the parameter optimization for car end connecting structures with various carbody dimenssions,various curve radiuses and different connecting methods.In this thesis,operating motion modeling and solution approaches for the car end dynamic parameter testing system is proposed.Controlling commands of acutators,with which hydraulic servo controlling system is employed to achieve the simulation for the motion of the car end,are obtained by spatial coordinate transformation as well as position inversely solving algorithm.The overall proposal for the mechanical structure of the dynamic parameter testing system for car end,a six-DOF motion simulating system as well as a flexible car end structure assembly are depicted in this thesis,and strength verification for the main load-bearing components of the dynamic parameter testing system for car end is conducted to verify that the entire static strength of the testing system complies with the requirements.The testing and controlling principle of the dynamic parameter testing system for car end is introduced in this thesis,including software section,hardware section and technical parameters of the devices needed during testing as well as the layout of sensors.This thesis proposes a dynamic parameter testing system for car end structures,which simulates the motion of the car end structures under various working conditions,to obtain the relative posture and parameters of the car end connecting components.The testing capability and the accuracy of the testing system developed in this study is validated by comparing the testing results with the FEA analysis.With the comparison between the testing results and the FEA analysis,the accuracy of the latter is steadily improved,to provide a guideline for top-down design.Indictors such as coupler swing angle,windshield angle,car end offset,minimum distance of a car end wall contour to its adjacent vehicle end surface,and force condition are optimized based on the testing results under various working conditions,to evaluate the performance of the car end connecting structures under different working conditions.