Research On Torsional Characteristic Of Separate Frame Construction For A Light Off-road Vehicle

With the popularity of automobiles, people gradually pay attention to lightoff-road vehicles, owing to its high trafficability and handling stability. When drivingon the poor road, vibration and impact will be passed to the body through the frame.As the deformation of suspension, body would inevitably produce certain distortion,therefore the analysis of body structure’s movement and structure is an essential link.For the separate frame construction of light off-road vehicle, the form and quality ofbody and frame structure have a direct impact on the life and performance of thevehicle. Sufficient strength will be able to ensure the fatigue life of body structure,and enough stiffness will be able to ensure the requirements of the assembly and use.In the design of automobile body structure, checking for the stiffness and strength ofbody structure is one of the designer’s main jobs. Body structure has complex spatialstructure and its stress distribution is more complex, in the past, experience oranalogy method is adopted in the design of body structure, which can causeexcessive or insufficient strength of body structure. Therefore, the research methodwhich combines simulation technology with experimental technology is of greatpractical significance.In this paper, choosing the separate frame construction for a light off-roadvehicle as the research object, the theories and methods of finite element method(FEM) as the research foundation, established the finite element simulation analysismodel of light off-road vehicle. Then, it makes the stiffness analysis, strengthanalysis and modal analysis under some specific conditions. In this paper mainly dothe following works:(1) Based on the theory of finite element modeling, the CAD geometric modelof the separate frame construction has carried on the finite element pre-treatment,and then a finite element analysis model of light off-road vehicle is established.(2) The separate frame construction is carried the analysis of the torsion andbending rigidity, torsion and bending stiffness value of the body structure is obtainedby the relevant calculation, the main opening deformation of the body structure arealso analyzed.(3) On the working conditions of torque and brake combination, torsion andturns, diagonal dangling, ultimate torsion of unilateral wheel and diagonal wheel, theseparate frame construction is carried the static strength analysis, the stressconcentration area of the body structure has been obtained, and then to check theresults of the analysis.(4) This paper briefly introduces the related theory of modal analysis, after thatthe free modal analysis is taken for the light off-road vehicle. It gets the modalfrequency and vibration mode of the light off-road vehicle, and then the results of modal analysis have been analyzed.