The Analysis Of Static & Dynamic And Fatigue Life For A SUV Separate Frame Construction

The market share for sport utility vehicles is becoming increasingly very fast in recent years. Many medium and large auto companies are stepping up the work of research and development the new model of SUV. The SUV for research is used of non-load-type body structure. This structure has both of saloon car's ride comfort and off-road vehicle's performance. The body and frame structure is the main load-carrying components for the non-load-type body structure. The performance indicators of body and frame structure must meet the performance requirements of automotive products. This requires us to check the performance indicators. The results can provide a reference for the research of the follow-up and new models.The research subject chooses a certain type of SUV to make the static strength analysis, stiffness analysis, modal analysis and fatigue life analysis. The specific research contents as follows:The modeling process of SUV non-load-type body structure.has been studied in detail. The research subject uses the finite element software HyperMesh to establish the finite element model for the SUV car body and frame after the geometric model.being simplified. The issues such as unit type selection, the quality control and connection handling are given a detailed account in paper. The finite element model takes into account the model accuracy and model efficiency of the computation.The finite element model which is established as before is carried the static strength & stiffness analysis and checking. The stress concentration has been found out in the vehicle structure. The bending region and the torsional stiffness values are achieved through the analysis. Meanwhile, the deformations of the main opening in the car body are obtained through the analysis.The theory and significance of the modal analysis have been introduced in paper. Then the modal analysis is taken with the finite element software MSC.Nastran for the SUV vehicle. It gets the modal frequency and mode shape of the SUV car body through the modal analysis. On this basis, the rigid-flexible coupling model and the road spectrum are established with the finite element software MSC.ADAMS and the theory of multi-body dynamics. After that the multi-body dynamics simulation on the B-grade road has been taken, in order to obtain the load spectrum of fatigue life analysis.Combined with related analysis results, using the finite element software MSC.Fatigue makes the fatigue life analysis for SUV car body structure. The contour results of fatigue life and the contour results of fatigue damage are obtained through the analysis. The serious fatigue damages in the car body are found at the same time. The service life of the SUV cars on the road on the B-grade random schedule and the minimum vehicle driving ranges are gained after the fatigue life analysis.