An FEM Analysis And Optimization Of A Mini Bus Frame

The FEA is an efficient tool of modern engineering. It would bring us dramatic effect in many aspects, especially in optimizing bus structure shortening the cycle and reducing the cost of developing new models. Applying the finite element technique to analyze the structure, put forward better opinions to satisfy the body's requests in stiffness and strength, become the main part designing. Frame is an important assembly bearing loads of an automobile. All kinds of loads will pass to it. So the performance of frame structure affects whether the automobile design is successful or not。In this paper, by the software, the frame 3D model, FEM model of mini bus was analyzed. The major research contents and related conclusions of this paper are as follows: firstly,The structural analysis of the vehicle frame were discussed, the stress distribution,the static bending,torsion stiffness,fatigue life of frame are calculated , then the natural modals are analyzed. Secondly, In this thesis, ANSYS/LS-DYNA, which belongs to the highly nonlinear finite element software, is applied in the numerical simulation analysis for the whole car frontal crash.,This research can be a method to validate the test and the simulation each other, shorten the passive safety test period. The car crashed rigid wall at velocity of the 48 km/h, then acceleration analysis, distortion analysis, energy absorption analysis of the whole car were carried on. Result of simulation indicated that the result can basically satisfied the crash safety statutes. Contrasted related literatures, in the thesis the simplification model is a fundamental accurate, its result of analysis is also fundamental accurate, matching basic regulation of numerical simulation of the crashworthiness;Finally, The topology optimization of the mini bus frame by means of OPTISTRUCT software.It can acquire the best distribution of material while containing or improving the performances. It makes the complicated structures being neatly and reasoningly selected in concept design stage.It is a valuable tool for designers since it can provide novel conceptual designs. This work is an attempt to introduce the optimal design of topology in the initial stage of design of the frame to obtain better design of structures . By adopting the homogenization method ,the topology optimization design for the frame is made under the conditions of bending and the torsion.After computing the frame topology is achieved,which provides basis for the number of distributions,location and the method of strengthening of crossbeams.The generalization designing method of the structure of a mini bus is also provided.The application of the technology of the topology optimization in the automobile structure design is realized。Through the analysis on the mini bus frame the conclusion come out to be: Using the FEM analysis during the initial stages of design has greatly reduced the development cycle and cost, enhance quality; Considering the accurate rate of the analysis results and the time cost to build the whole model.The study of this paper has referenced on other structure type design of the frame.