Strength And Fatigue Life Analysis Of The New MB-1 Carriage Bogie Framework

In recently, with the callings becoming more and more seriouse, the people pay attention to fatigue life of component which relative to security and economics. So, they all put forward frondose requests for fatigue life of component. In the twenty-fist century, the fatigue-life forecast of component is applied in companies all over the world step by step. In some circumstance, people can forecast the exact position of fatigue damage and compare the difference fatigue life exists among components under definite load which are made in different method. During the design and modifying of new part, we make fatigue life analysis in order to get the reliable fatigue life of component As result , we can shorten researching cycle and save a lot of experimental outlay. The traditional method is that make experiment with a locomotive sample in test-car yard and road, which waste long period and a lot money. However, this method not only can't find out the root of problem, but also do the test after manufacturing the vehicles and that is to say: we can only test it but not forecast. Presently, in the fierce competitions in market, the products renovation become increasing and mature products improve continuely to adopt to market requests. Therefore, the importance of fatigue life analysis of component in product design and improvement is regarded by researcher.At present, the trains of increasing speed on main railway lines have worked. The carriage with high speed and carriage with heavy load are the future trend established. Bogie framework is one of the most important carrying components in rolling stock, which is the structure of a non-steering for rolling stock. A great of research both at home and abroad indicates that failure models of rolling stock framework are usually fatigue breaking under the function of random load. In order to guarantee the safety of traveling train, it is important to analyze the fatigue life evaluation and reliability design. This paper analyzes the finite stress&strain of bogie framework and welding seam, and then its fatigue life based on finite element analysis software Hypermesh, MSC.Patran/Nastran and fatigue software, so we deduce reliable prediction of fatigue life and save a great deal of experimentation cost. The thesis has significant guiding meaning for product design.This article is divided into five chapters altogether。The research content is as follows:1. ExordiumThe first chapter is exordium, which describes the meaning of subject and points out the situation of bogie framework at home and abroad. The main content and method of subject are also introduced.2. The introduction of the finite element analysis of fatigue.This chapter simply introduces the conception of the fatigue and the radical theory of the destruction character, from this we can know which type of destruction is the fatigue destruction and the common analysis of the fatigue. In the other hand, it introduces the radical thought of the finite element analysis of fatigue, and it shows the frame of use the finite element analysis software to the fatigue analysis, namely the radical step of the finite element analysis of fatigue. Finally it simply introduces the radical module and the merit of the MSC.Fatigue which is used in my paper .3. The finite element account of the bogie frameworkFirstly, set up the 3D solid model of the bogie framework, and simply introduce the software of the finite element named Hypermesh and MSC.Nastran. Secondly, with the combining way of the shell element and the solid element, it controles the number of the elements and the nodes used by the manually plotting out. We can separately use the different thickness shell element to simulate the welding seam. With the analysis of the bogie framework configuration character and its travelling ,we can ascertain the various working load of the frame, and make several typical load goings and its boundary condition. As it can be drown that the frame's rigidity can satisfy the working desire, the max stress usually happened at the welding seam joint between the base plate and the side girder.4. The fatigue analysis of the bogie frameworkIn this chapter, we make the fatigue analysis of the bogie framework under nominal stress method. Although the impersonal situation of experiment is limit, we make use of the random load in order to simulate practical condition, Moreover, aiming at fatigue analysis of weld-seam, we modify the S-N curve of material and then deal with the analysis. At last, the result indicates that the bogie framework of fatigue life is satisfied with the need in practical work.5. The summery of the thesisWe sum up the main finished work and conclusion in this thesis. And then give the shortages exit in the article. At same time, we put forward the direction of further research.