Finite Element Modeling And Analyzing Of Automobile Drive Axle Housing

As the mainly carrying and passing components of the vehicle, the automobile drive axle housing supports the weight of vehicle, and transfer the weight to the wheel. Through the drive axle housing , the tractive force,braking force and lateral force act on the wheel transfer to the suspension system,frame or carriage. Because the driving condition of the vehicle is very complex, as a result, the drive axle housing affect the life-span of service of vehicle, so the drive axle housing need to have enough intensity and rigidity, and good dynamic performance, the reasonable design of the drive axle housing can also improve vibration comfortableness and ride comfort of vehicle. The finite element method is used far-ranging in the design of vehicle structure, because it can solute mechanics problems which have arbitrary structure,shape or boundary condition. All kinds of vehicle parts can use FEM to perform static analysis, normal analysis and dynamic analysis. Today, using normal analysis and dynamic analysis to solute actual engineering problem is more and more important, and also can perform nonlinear analysis base on the trait of the structure. The work of this paper is based on FEM static and dynamic theory, the 3D model of the drive axle housing was established with the software Pro/E. Based on this model, the finite element analysis was simulated in computer under the circumstances of MSC.PATRAN and MSC.NASTRAN, and also summarized relevant norms about setting up analysis models and relevant analysis conditions which can make analysis fast, received useful conclusion. The main contents and conclusions of this paper are as follows: (1)The overall thinking and precautions of established model with Pro/E, and reduction method of the geometry model has been summarized. Take one drive axle housing of a medium-sized cargo truck as an example, putted forward the thinking of simplifying geometry modeling of the drive axle housing, and introduced how to use Pro/E to set up the geometry model of the drive axle housing in standardized modeling step. (2)According to the established process of finite element model with preprocessor and post processor software MSC.PATRAN, the paper has introduced the concept of simple geometry and complex geometry in MSC.PATRAN; and summarized several geometry noncontinual conditions, advanced corresponding solution for every problems; concluded the function of Group and the important purpose in modeling; summed up the operation of hard geometry and the way to build them; The category and purpose of auto mesh generator, the method for controlling mesh density, and the theory of how to examine element quality in MSC.PATRAN have been recommended in this paper. These all built a good foundation on clearing geometry and meshing geometry. According to the modeling theory and the operation summarized before, the modeling process of finite element model of the drive axle housing was introduced in detail. This provided a series of canonical modeling step for establish a finite element model of drive axle housing with shell element. (3)There are four conditions in static analysis of the drive axle housing : Upright loading condition, the maximal tractive force condition, the maximal braking force and the maximal lateral force condition. The method how to deal with loading and constraint in four conditions is presented in this paper, and built corresponding analysis file for every condition in MSC.PATRAN. The result of stress and deformation of drive axle housing in four conditions have accomplished with MSC.NASTRAN. In upright loading condition, the dangerous position, which has the most stress, is near the crescent and the bolt hole, and the most deformed position is near the root of center flange, the stress and deformation of drive axle housing distributed reasonably. In upright loading condition, the drive axle housing with body element was modeled in Hypermesh software, after compared with the calculation results of two kinds of models, we could see that utilize the shell element to set up analyzing models is feasible. (4)The key points of modal analysis of drive axle housing was researched, and built the modal analysis condition of drive axle housing in MSC.PATRAN, after referred to MSC.NASTRAN and calculated, the first twenty natural frequency and vibration shape were achieved, and we could know that the seven natural frequency far from road excitation, it can't cause resonance of the housing.