| With the diversified characteristics of the world economic development,railway freight transport has become an important driver of world economic growth.Since the successful holding of the first International heavy-haul Conference in 1978,heavy-haul freight has become an important solution to enhance the capacity of railway freight transport and is internationally recognized as the development direction of railway freight transport.Increasing the axle load of freight cars and reducing the self-weight of car bodies is an effective way to solve the problem of railway heavy-haul freight transport.Because the load of large axle load truck body is worse than that of ordinary truck in the course of line operation,higher requirements are put forward for the performance of large axle load truck body.In this paper,the 40-ton axle load export ore car body,which is the largest axle load railway gondola independently developed by Chinese enterprises,is taken as the research object.Based on the finite element analysis theory,the static strength,stiffness,mode,stability and fatigue strength of the 40-ton axle load export ore car body are analyzed and calculated by using Hyper Mesh software and Ansys software.At the same time,the calculation results of the static strength and stiffness of the car body structure are compared with the test results,and the weld fatigue problem occurred in the position of the car seat is optimized.The specific research contents and methods are as follows:(1)This paper briefly describes the development of heavy-haul railway freight cars in the world,introduces the research on heavy-haul railway freight cars at home and abroad,and explains the important significance of strength analysis of 40-ton axle load export ore car body in this paper.(2)The structure composition and characteristics of the 40-ton axle load export ore car body are introduced,and the finite element model of the car body is established by using Hyper Mesh software.According to the requirements of the American AAR M 1001-2015 "truck Design and manufacture Code",11 static strength calculation conditions are determined.The static strength and stiffness of the car body finite element model are calculated by using Ansys software,and the calculation results are analyzed.(3)The static strength and stiffness of the car body structure are tested and verified according to the standard of TB/T 1335-1996 " Specification for strength design and experimental evaluation of rolling stock car body ",and the test working conditions,loading methods and the distribution of test points are introduced.At the same time,the loading condition of the car body finite element model is modified according to the test situation,and the calculation is carried out.The test results are compared with the simulation results,and the causes of the errors are analyzed and discussed.(4)According to the basic theory and related requirements of modal analysis and stability analysis,the free mode and buckling stability of the 40-ton axle load exit ore car body model are calculated.The natural frequencies,main natural vibration modes and unstable parts of the car body under empty and heavy conditions are obtained respectively.(5)The feasibility of fatigue assessment based on American AAR standard and British BS7608 standard is analyzed.12 evaluation positions of car body are selected,and the fatigue life is predicted according to AAR standard and BS standard.(6)In view of the weld fatigue cracking phenomenon in the process of vehicle operation,the original structure is analyzed in detail and the fatigue evaluation is carried out by using the main Smurn curve method.The position of the dialing seat is optimized,and the fatigue analysis of the optimized structure is carried out. |
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