Fatigue Characteristic Analysis And Structural Optimization Design Of Express Container Flat Car

In recent years,my country’s railway transportation has developed rapidly,and its transportation capacity and efficiency have been continuously improved,which has made important contributions to my country’s economic construction.Speed increase and heavy load are two important directions of the current railway freight development,especially in the case of passenger and freight co-tracking,in order to improve the railway’s transportation capacity and efficiency.As a special railway wagon,container flat cars have many advantages and have been widely used at home and abroad.The thesis establishes a finite element model and a rigid-flexible coupling dynamics model for a fast container flat car designed by a company to study the fatigue characteristics of the frame and the optimization design of the car body structure.The specific research work is as follows:(1)Introduce the development history and status quo of domestic and international railway freight transportation,point out the background and important significance of the research on this type of flat car,and summarize the current status of domestic and foreign related research based on the research content of the thesis.(2)The finite element analysis is carried out on this type of track flat car,including the frame and the car body.Use Solid Works to build a three-dimensional structure model,and build a structural finite element model in Hyper Mesh.Perform sub-structure analysis on the frame and car body,and verify the accuracy of the sub-structure analysis results,to obtain the flexible body files required for the rigid-flexible coupling simulation analysis,and introduce the theory of the sub-structure analysis method and the process of generating the frame flexible body.At the same time,ANSYS is used to carry out modal analysis on the frame and car body to understand the structural characteristics and dynamic characteristics and provide guidance for avoiding resonance.(3)A rigid-flexible coupled multi-body dynamics model considering the flexibility of the frame was established in the Simpack software,and the track irregularity of Qin Shen Line was added as an external stimulus,and the difference in the vibration response of the flexible frame and the rigid frame was compared and analyzed to analyze the necessity of considering the flexibility of the frame.A modal stress recovery method based on a flexible body is used to simulate and calculate the dynamic stress,and the dynamic stress results of the focus node of the frame under different working conditions are obtained.The fatigue characteristics of the frame are analyzed according to the dynamic stress,and the effect of different factors on the fatigue of the frame structure is explored.(4)The structural strength of the car body was checked,and it was found that it can meet the requirements of relevant standards and has an optimized design space.Taking structural strength as the constraint condition and minimizing the car body mass as the objective function,Opti Struct is used to optimize the size and topology of the car body structure in turn,and check the overall performance of the optimized structure,including strength and modalities.And dynamic performance.In the end,the mass of the car body is reduced by about 11.56%,and the performance of the optimized structure meets the requirements of relevant standards,which effectively realizes the lightweight structure.