Analysis Of The Strength And Fatigue Life Of The Car Body Of The Meter Gauge Ballast Hopper Car

With the change of global economic situation and the rapid economic development of all countries,the demand of foreign countries for railway freight wagons is increasing year by year,which also stimulated the growth of China's freight wagon exports.On this basis,customers also put forward new and higher requirements for the quality of freight wagons.Therefore,it is necessary to carry out static and dynamic characteristics analysis and fatigue life calculation to check the safety life of the car body before production.This paper takes the 1000-meter gauge ballast hopper car(Hereinafter referred to as hopper car)exported to Thailand as the research object.The static characteristic analysis,modal analysis and fatigue life analysis are carried out.Referring to the design drawings,UG is used to build the 3D model of the car body structure of the hopper car,and then the assembly model is imported into the ANSYS Workbench to carry out the pre-processing analysis,including the model simplification,model inspection and repair,grid division and so on.And finally the finite element analysis model of the car body structure of the hopper car is established.Using the above finite element model,static structure module of ANSYS Workbench is used to carry out static analysis of the car body structure under each working conditions.The results show that the maximum stress of the car body structure under each working conditions is less than the allowable stress of the material under various working conditions,and the static characteristics of the hopper car body structure meet the use requirements.The modal analysis module of ANSYS Workbench is applied to the free modal analysis and constrained modal analysis of the finite element model of the hopper car.The results show that the ratio of the vehicle's first mode frequency to the calculated bogie nod natural vibration frequency(2.4 Hz)and floating natural vibration frequency(2.8 Hz)is greater than1:4.The natural vibration frequency of the car body is greater than 10 Hz which meets the requirements of TB/T 3115-2005 standard.Therefore,the hopper car body will not resonate during operation.According to American AAR standard,the calibrated stress distribution is obtained by loading the load spectrum on the corresponding position of the car body.Then according to the change of stress,the corresponding cyclic characteristics are obtained.According to the welding grade of solder joints in the standard,select the corresponding parameters of S-N curve and Goodman diagram.Calculate the fatigue life of the car body structure,and check the fatigue life of the hopper car body structure.According to "BS EN 1993-1-9: 2005 Euro code3: The design specification of steel structure",further evaluate and analyze the fatigue life of the hopper car body structure.The results show that the corresponding cumulative damage value of each weak part of the hopper car body(refer to AAR standard)is less than the theoretical value "1",which further shows that the hopper car body structure meets the requirements of safety fatigue life.And the fatigue life of the hopper car body is checked.