汽车桥壳文献出处：Paul D. FE Analysis and Optimization of Vehicle Drive Axle Housing [J]. Journal of Engineering Computers & Applied Sciences, 2015, 12(3): 21-35.
原文
FE Analysis and Optimization of Vehicle Drive Axle Housing
Paul D
Abstract
As a main part of cars, drive axle housing supports the automobile chassis and the carriage, passes weights to the wheels. Meanwhile, the vertical force, traction, braking force acting on the drive wheels are also passed to the suspension and the frame though the axle housing; therefore, it is playing as both loading part and transmission part. Because the axle is used frequently under complex conditions, their quality and property directly affect the overall performance of the vehicle and its used life, so the drive axle housing must have characteristics of sufficient strength, stiffness and good dynamic. Currently the traditional method has been difficult to meet the requirements of drive axle housing, while because of its many advantages; the finite element method becomes an effective way to solve the problem.
Keywords: Drive axle housing, Leaf spring, Collaborative Simulation
1 Introduction
As one of the main parts of truck, drive axle shell to play the role of a support vehicle load, and can transfer load to the wheels, at the same time, the driving wheel on the vertical force and tangential force, braking force and the traction), lateral force is through it passed to the frame and carriage, it play the role of a bearing load and transmit forces. In the car, drive axle shell under high load, especially when the car loaded with high speed in the uneven road surface, will produce a big road impact load of the wheels, under the action of strong impact load, the dynamic behavior of the overall car will be from the drive axle shell parts inside and outside the influence of the vibration of the incentive to produce, may even make the bridge shell produces a lot of dynamic stress, lead to crack, fracture, even seriously affect the safety of the vehicle. In automobile structure, due to the use of high frequency, drive axle shell has higher failure rate, however, the overall performance of the car and the useful life is
influenced by its quality and performance directly, this requires that it has enough strength, stiffness, and has good dynamic characteristics, in turn, to ensure that the car's stability.
2 The research status
Due to the development of computer technology, expanding the application range of the finite element method (fem), especially in the 1970 s, some famous auto companies began to apply the finite element method to the design of auto parts, raised a hot wave of finite element method (fem) in the automobile structure design, such as: ford using Nastran finite element analysis software, the finite element model with shell element definition unit, to the static analysis of car body, get the stress nephogram, high stress area is determined, and carry on the improvement of the corresponding structure. By the end of the 80 s, Japan Isuzu companies have all aspects of the finite element method is applied to every part of body design. And has a well-known Japanese company by using the finite element method is proposed for 2.5 times full of axle load of drive axle housing structure analysis standard.The famous automobile company in the conventional finite element is comparatively mature application field, its research focus has shifted to nonlinear analysis, transient response analysis, impact analysis of temperature field analysis and optimization design and analysis, etc. Due to the finite element analysis software such as ANSYS was introduced, and is widely applied in engineering practice, in recent years, many automobile company and scientific research institutions joint of drive axle shell finite element analysis.
2.1 Static structure analysis
"The automobile drive axle bridge shell under the condition of static finite element analysis under typical conditions was described, and the static structure analysis of drive axle shell, the analysis of drive axle shell has certain reference value for design improvement, but the literature is just to simplify the structure of drive axle housing for the static analysis, the results of the analysis has certain error." Dump truck rear axle shell finite element stress calculation" compare the original model and the reinforcement model in various typical working conditions of the static structure
analysis, fully embodies the advantage of finite element method (fem) and quick, economic and environmental protection, provides the basis for the drive axle housing structure improvement design;"ZL50 wheel loader type welding drive axle shell vibration modal analysis" in various typical working conditions are introduced, the static structural analysis of the drive axle shell, got the stress contours and strain contours, and make evaluation on its structure and performance, but the object of study is just drive axle shell, evaluation of the lack of integrity. " Automobile drive axle housing based on ANSYS finite element analysis of" stated the application of finite element method, ANSYS software of finite element analysis was carried out on the drive axle housing, and the analysis results compared with the traditional theoretical calculation results, shows many advantages of the finite element method;
" automobile drive axle bridge shell finite element analysis shows that the national standards of drive axle shell, the strength, stiffness, and the different thickness of the drive axle shell finite element analysis, the results show that the thickness of several bridge shell meet the evaluation indexes.
2.2 Dynamic analysis
"Automobile drive axle shell finite element dynamic is analysis of ANSYS software for static structural analysis and modal analysis. Through the modal analysis, obtained the low order natural frequency and vibration mode, and the experimental results are basically the same. "Drive axle integral finite element dynamic simulation" describes the test data is only on the surface of the drive axle shell vibration, dynamic analysis method is the data on the drive axle shell unit within the node, make up the lack of experiment, and provides research foundation for vibration noise. "Mini drive axle shell structural strength and modal analysis by ANSYS modal analysis was carried out on the drive axle housing, and obtained the low-order modal frequencies and their corresponding vibration mode, analyzes the results, drive axle shell dynamic design standard.
2.3 Fatigue analysis
Drive axle shell in order to make use of the finite element software static structure analysis, modal anal
ysis and the analysis of the fatigue strength, fatigue life
of drive axle shell distribution, and the service life of the most dangerous point value;" Automobile drive axle shell under the action of random load fatigue life forecast" drive axle shell to make use of Nastran static structural analysis and fatigue analysis, the fatigue life of drive axle shell distribution, and the service life of the most dangerous point value, and compared with the bench fatigue test data, the data is consistent. Drive axle shells to make use of the finite element method of fatigue analysis, drive axle shell, the distribution of fatigue life and the life value of the most dangerous point, provided the basis for its improvement.
2.4 Optimization analysis
Vehicle drive axle shell dynamic optimization design based on parametric drive axle housing for the reliability optimization, on the basis of this, adhere to the principle of overall lightweight, local reinforcement, continue size optimization, the results not only lightweight effect is obvious, and guarantee its mechanical performance. Drive axle bridge shell finite element analysis and structure optimization by using finite element software for structural analysis, and put forward improvement on the basis of the results of the analysis, again carries on the analysis, comprehensive evaluation of the
results of the analysis, after the effectiveness of the proposed improvement measures. To sum up, in recent years, with the development of the computer, the finite element technology gradually mature, expanding its application field, application of finite element method (fem) to drive axle design, can effectively shorten the development cycle, reduce production cost, and improve competitiveness.
3 Finite element models
Create a bridge shell entity model is a priority for the finite element analysis on it. Because its structure is complex, irregular surface is more, directly using ANSYS Workbench's own entity modeling module of drive axle shell model created there is a big difficulty, therefore, in this paper, with the aid of Solid works software strong modeling ability, create physical model of drive axle housing. When establishing finite element model, which requires it to reflect the important mechanical properties of the model itself, and USES the appropriate unit types, try to decrease the number of
units, in order to make sure to get a precise finite element calculation results as well as shorten the calculation time, so to simplify some of the minor, the dangerous structures, while retaining the original structure of drive axle shell body, make its can still reflect the actual structure of the main characteristics and mechanical characteristics, in order to meet these requirements, set up the model,
the model is correct, geometric elements, on the basis of relevant and mechanical properties of the model under the premise of do not change, its structure is necessary. For building solid model is made up of drive axle housing, leaf spring, plate spring and assembly model is composed of main reducer shell. Drive axle housing is stamping steel welded integral, including: bridge shell body and axle tube, bridge shell body made of steel plate stamping welding.
4 Bridge shell finite element model
Create a finite element model is a necessary condition for finite element analysis, it is also important link, will create the entity model of Solid works first imported to ANSYS Workbench, and then, using ANSYS Workbench material definition, contact to set, meshing, finite element model. As pretreatment module of ANSYS Workbench, the situation has a direct and significant impact on the finite element analysis. ANSYS Workbench provides powerful ability of automatic classification, through the practical intelligence can be realized by default, complex model of meshing grid can be achieved by changing parameters real-time updates. Based on ANSYS Workbench mesh with flexibility, can be achieved for different structure or targeted meshing characteristics, in order to ensure the accuracy of finite element simulation. Analysis, finite element model of nodes and the cells are involved in calculation, in the ANSYS Workbench, you can preview based on grid, to assess whether it is reasonable, and through th
e elaboration, has higher precision of the calculation results, however, refined grid will make analysis and calculation time, and even has higher request to the hardware, it increases the cost of computing, therefore, grid refinement to appropriate, can also through the choice of changing the type of unit to reduce the amount of calculation. The drive axle housing was established based on Solid works assembly model, based on the collaborative simulation