Vibration Characteristics And Fatigue Analysis Of Axle Box Springs For High-speed EMUS

In recent years,with the development of high-speed railway in China,more and more high-speed EMUS have been put into operation.At present,the vibration attenuation of highspeed EMUS is carried out by the combination of one-series suspension and two-series suspension.Axle box steel spring(also known as a series of steel spring)is an important suspension component of high-speed EMUS,and its performance affects the running stability and safety of high-speed EMUS,and its importance is self-evident.But in the process of vehicle operation,some lines of high-speed emu far below its design life,the service life of steel spring steel spring fracture occur frequently,even directly affect the running safety of high-speed train,if steel spring fatigue fracture problems can’t be settled effectively,is bound to cause serious security threats to railway and great economic losses.In this thesis,a certain type of axle box steel spring of the EMUS is taken as the research object.Through the finite element simulation calculation,the bench test is carried out on the high-frequency excitation test bench with a single wheel,and the fatigue fracture of the steel spring is deeply studied from the perspective of vibration response,so as to find the The root cause of the failure.A rigid-flexible coupled EMUS model considering the elastic mode of the steel spring is established,and the dynamic stress and vibration response of the steel spring under different track excitations are simulated and analyzed,so as to verify the cause of the fatigue fracture of the axle box spring,and the fracture of the axle box steel spring is simulated and analyzed at the same time.The impact on the vehicle dynamic performance,the dynamic characteristics corresponding to the fault are summarized,and the method and basis for the monitoring of the train running state are provided.The main contents of this article are as follows:1.The axle box steel spring was visualized by 3d software.The steel spring was imported into Hyper Mesh software for mesh generation and prestressed loading,and then imported into ANSYS software to calculate the steel spring modes;High-frequency excitation frequency sweep test was carried out on a single wheelset high frequency excitation test bench.Frequency domain and time-frequency analysis were carried out on acceleration signal and dynamic stress signal of steel spring under frequency sweep,and the dynamic stress data were normalized to obtain the stress data under single vibration input of steel spring,and the amplitude-frequency characteristic curve was drawn.2.Establish a rigid-flexible coupled EMUS model considering the elastic mode of the steel spring,and simulate and analyze the vibration response of the vehicle,the dynamic stress of the steel spring and its vibration transfer characteristics.The simulation conditions are divided into wheel polygon excitation,sleeper span impact and random Excitation,and according to the dynamic stress data under each working condition,the fatigue life of the steel spring is estimated.3.Calculate the parameters after the steel spring fracture of axle box,simulate the steel spring fracture in SIMPACK by setting the parameters,simulate the running stability and safety of 250 km/h EMUS after the steel spring failure,and analyze the train dynamic performance after the steel spring fracture.