The Analysis Of Statie&Dynamie And Fatigue Life For A White Body

The sample car this paper studied was unit type of the cab and car frame, Its loadcondition was more special, different from single car frame structure and stress stateof single car cab. According to static strength analysis，stiffness analysis，modalanalysis and fatigue life analysis of car body, We provided three improvementmeasures. Finally, the performances of the car body were enhanced by structuralimprovements. The research contents as follows:The modeling process of the car body structure has been studied. The geometricmodel is cleared up and simplified by using finite element software HyperMesh. Theissues such as element selection，the quality control and connection handling weregiven a detailed account in paper. Then the modal analysis was taken with the finiteelement for car body. Compared the results of calculating modal with experimentalmodal, we verified the accuracy of the finite element model of car body.The finite element model which has been established as before was carried thestatic strength&stiffness analysis. The deformations and high stress area have beenfound in the vehicle structure in bending condition and torsional condition, and thebending stiffness and the torsional stiffness values were achieved through the analysis.Meanwhile，the deformations of the main opening in the car body are also obtainedthrough the analysis.According to experiments, the finite element model was carried the static strength&stiffness checking. At the same time, Evaluating bending rigidity by using smoothdegree of the overall body deformation, Evaluating torsional stiffness by usingsmooth degree of the overall torsion angle.Combined with related analysis results, using the finite element softwareMSC.Fatigue made the fatigue life analysis for the body structure. the contour resultsof fatigue damage and twenty elements of the most dangerous were obtained throughthe analysis.In view of the above analysis results, three measures were taken to improve thebody model. In stiffness, strength, the improved model has a certain increase, thestress concentration phenomenon and the size of the fatigue damage were alsoimproved.