Fatigue Analysis And Research Of Rear Torsion Beam Of Vehicle

With the growing of automobile production and sales, consumers and producers pay more attention to the quality of automotive products, and service life of the automobile and spare parts has become one of the issues that the users are most concerned about. In the development process of automobile, fatigue problems in the design process are found by automobile enterprises through vehicle proving ground durability test, after improvements, the test will be again performed, and it will repeat several rounds, thus the time of vehicle development is delayed. In the development process of automobile, the weaknesses of design are identified before the test by using the CAE fatigue life analysis technology based on the tests, then some improvements will be done, and the number of vehicle proving ground tests can be reduced, that is to say the vehicle development cycle will be largely shorten.In this paper the vehicle rear torsion beam is regarded as the research object, and the fatigue life analysis is performed from the multi-angle, multi-field. The paper proposed a method of fatigue simulation analysis based on the combination of road test and the CAE simulation technology for the automobile chassis key parts, and the fatigue analysis of automobile structure can be promoted. The rear torsion beam flexible body is obtained which establish vehicle rigid coupling model required, after the establishment of the torsion beam finite element model and make of modal analysis. Calculated torsion beam unit load stress field by utilizing the principle of inertia release, and verify the accuracy of the finite element model by the use of virtual strain gauge to correlate the FE model’s results with measured strain gauge data. A vehicle wheel center as dynamic analysis boundary conditions is measured on strengthening-road, and after the establishment of vehicle rigid coupling model and simulation analysis needed to get the torsion beam fatigue load spectrum. Finally, Stress influence coefficient method is used for torsion beam fatigue life prediction. What’s more, simulation results were compared with the road test results. The results show that this method can ensure the accuracy of the finite element model for fatigue analysis and boundary conditions, so that the fatigue life of the torsion beam rear vehicle simulation analysis is more accurate, and provides a theoretical basis for fatigue analysis based on the structural design and improvement of the rear torsion beam of vehicle. The method is also applicable to the fatigue analysis of other automobile chassis parts. Finally, according to the results of the fatigue life analysis, the contribution of different test roads on rear torsion beam fatigue damage are analyzed, and the sensitivity of factors affecting the fatigue life is analyzed.