The Finite Element Analysis Of Car's Rear Axle And Prediction Of Fatigue Life

Rear axle is the last general assembly of car transmission. It is locates at the end of the automobile transmission parameters. The basic usage of rear axle is that it is bearing the load when engine output the tensional moment, then send it to drive wheel, aiming at driving. Driving elements basic axle housing will affect the car's security and reliability. It is the important safety critical component and functional part. Because the disadvantage of the making progress, the small micro cracks always exact. Fatigue as a failure mode, is the extension and confluence of failure mode. Macroscopic crack will destroy it at last. In order to avoid accident and decrease loss, people always research the methods of measures on improving the fatigue strength, exploration of more exact of life.Because driving axle housing is complicated, so it is difficult to use classical mechanics to have the exact analysis of the strength. We always use the simplified and binding experience. Such calculation and analysis is obviously sketchy. Finite Element-Fatigue calculation can offer fatigue Life distribution map of parts surface. At the design stage, judge the position of parts fatigue Life. Design modification can avoid unreasonable Life distribution at first. Finite element method can decrease the number of test prototypes. Shorten period of development, reduce cost, enhancing market competitiveness.This article uses the finite element method to have a detailed research of rear axle's strength and stiffness.On the basis of reading researches at home and abroad, I do the job just like this,At first, the author introduced the basic principle and operation mechanism of rear axle systematically, analyzed the present study of rear axle at home and abroad and the brief study on history of fatigue life.Then, chapter two is introduction of finite element methods development and analysis progress. The usage of the finite element methods in automobile industry. Introduction of basic concept and design method in fatigue and finite element and application software of Patran,Nastran,Fatigue .Chapter three introduced the rear axle's structure design and strength analysis. Put forward three key technologies.Chapter four, simplify geometric model of rear axle. Let it introduce into the software of MSC.Patran. Build up the finite element model of rear axle. Finish the internet partition and material properties. Input the constraint handling and load. To have static analysis in rear axle, have constant load, and dynamic load coefficient. Use MSC.Nastran to calculate and analysis rear axle's strength and stiffness. Calculate stress and strain, under maximum load. Find the position of dangerous point.Chapter five will introduce fatigue analysis and calculation methods with the method of software MSC. With MSC.Fatigue to set up the model of fatigue life finite element and try to identify dangerous point. At the end of this part the author predicted the fatigue life of rear axle and analyzed the mode.Determined by model partition, finite element partition and stress analysis. I have the results of the car's rear axle strength. This study provides a theoretical basis for car's improved design and offering structural optimization. Have the theoretical guidance meaning for new products development.