The Evaluation Method Of Service Life And Reliability For Urban Rail Vehicle’s Air Spring System

Air spring is the main damping components of the modern rail train sit vehicle, whichcan effectively improve the rail vehicle dynamic performance.The present feature of air spring system has some disadvantage like complex-strictureand fluid-structure, which make a lack of method and equipment to analyze the residualservice life of air spring to the maintenance man of urban rail way system For reason ofdriving safety, most air springs are mandatory scraped before they arrive their service life,this situation causing a huge economic losses. Therefore, this topic present an assessmentmethod which based on pseudo fatigue test to evaluate air spring system life, and theinternal mechanism of the air spring system damage were studied. The advantages ofpseudo fatigue test were short test period and low test cost compared with the real test.Present foreign and domestic research of pseudo fatigue test focused very much on thefatigue life prediction of truck frame, wheel set and car body which are metal parts. Theresearches focused on the dynamic stress and fatigue characteristics are still in a fledgingperiod, currently, only to the rubber part like rubber pile side bearing, Rubber ball jointand rubber spring of axle box which are simply constructed and regularly framed.Through research, this paper puts forward a kind of method to evaluate the service lifeand reliability of air spring.This method has aimed at the train’s practical operationcondition, and also based on the multi-body dynamics and nonlinear finite element analysisand virtual fatigue life of joint simulation. This method has based on the actual vehicleoperation condition, first using the multi-body dynamics simulation for the air spring’sload-time history curve; then using nonlinear finite element analysis for the air spring’sstructure stress and strain results; finally, through the simulation analysis method toestimate the fatigue life of loading online under the running condition of the serviceabilityof air spring.The results of this study can provide important guidance to the urban rail vehicle’s air spring maintenance enterprise when determining the service life and reliability during theair spring’s "Detection Vacuum Period",and it has made up the gap in existing technology.And the results have the same certain reference significance for urban rail vehicles, generalrailway vehicle and high-speed emu optimization design of air spring design products...