Progresses on the Fatigue Reliability Research of China Railwayvehicles in Recent Decade

摘要

Main progresses are reviewed and prospected from four elements on the fatigue reliabilityanalysis research of China railway vehicles during recent decade.First,material fatigue database hasbeen moderately developed and an emphasis was placed on the systemized fatigue properties.Second,a great of on-line inspections have been performed on the wheel-track contact forces and servicestresses of key structures.A reliable vehicle dynamics simulation technique has been developed forsimulating the contact forces and a multi-variable quadratic regression approach has been proposed tocalculate the service stresses for recuing imperfect inspections.Third,systemized fatigue reliabilityresearches have been made on improved fatigue limit measurement,probabilistic S-N curves,scale-deduced fatigue behavior,design Goodman-Smith diagram,and reliability analysis approach toaddress on the real super-long life of railway vehicle's structures.Fourth,a critical safety state theoryis established to address the time-dependent off-round wheel wear and the interactive fatigue damagebetween components.Fatigue cracking threshold measurement is improved.And a fatigue crackgrowth modeling is developed to cover entire physical process from the threshold to the fracture.Theaxle critical safety sizes are determined under considering the off-round wheel and the wheel criticalsafety wear sizes are measured to ensure the axle expected safety life.All researches are valuable tobe further studied.