Vibration Characteristics And Parameters Matching Research For Underneath Suspended System Of High Speed Trains

With the rapid development of high speed trains technique,the operating speed has been rised for several times,which draws great attention to the vibration increased by car body and underneath equipments.In orde to ensure the safe and steady operation of the high speed trains, the research of the vibration transfer discipline becomes increasingly significant. This thesis mainly consider the underneath suspended system and analyze the equipments’ vibration transfer principle, car body modal changes, car body suspended equipment parameters, equipment layout scheme and roller rig vibration tests. All of above are based on the rigid flexible coupling dynamics.First of all, this thesis introduces the backgrounds and research methods of high speed train underneath equipment system and its development status at home and abroad. The researches for the underneath suspended systems at the present stage are also included.After that, the thesis presents the basic theory of vibration transformation, then carries out analyses and comparisons on evaluation methods of vibration isolation insertion loss, force transfer rate, power flow and vibration level difference. In addition, the expressions of vibration isolation concerning underneath suspended system, and car body interaction.Then, taking the flexible coupling vibration of car body and underneath equipments as analysis target, the flexible body modeling process is introduced in detail, and the three-dimensional coupling dynamic system model of underneath equipments and car body is established.Finally, the relationship between flexible structure and dynamics for high speed trains is analysed, and the analysis is focused on the coupling vibration features between elastic car body and equipments.Through the study on the car body vibration reponses with varying the underneath equipment parameters, the vibration reduction method is given.The feasible layout scheme of underneath equipment is discussed.The roller rig test is carried out to validate the numerical simulation.