| In this article, a certain type of loader drive axle housing in liugong is exampled as the research object. The 3D software Pro/Engineer, the finite element analysis software ANSYS and ANSYS Workbench which combined with the nominal stress method are used synthetically, completing the establishment of the drive axle housing entity model, the finite element static analysis of typical mode, the fatigue life assessment of the nondestructive bridge shell, and studying the crack defects influence on stress distribution of drive axle housing. According to the above analysis and the result s of the study discussed,proposing two repair plans in view of the dangerous section of the fatigue crack defect- reduce the stress concentration and change the material.(1) According to the stress of the drive axle housing and the structural characteristics, with the method of theoretical mechanics principle, calculating the fore of drive axle housing under the stress of various typical working conditions. By using Pro/Engineer and ANSYS, establishing the finite element model to Simplified drive axle housing,completing the finite element static analysis of drive axle housing under typical conditions,checking the strength and stiffness of drive axle shell.(2) At first, it corrects the s-n curve of drive axle housing material. Secondly, through the modal analyze on drive axle housing,acquiring the dynamic characteristic of drive axle housing. Finally, combining the analytic results of finite element static, with the CAE virtual simulation bench test method and the nominal stress method, evaluating the fatigue life of it and comparing it, and obtaining the distribution map of the fatigue life of drive axle housing, locating the position of dangerous cross-section.(3) To study the dangerous crosssection crack defects affect the stress distribution. Research results show that the stress value is obvious at the crack tip, a little bit large, with crack width increases, the less of the crack tip stress value. With the increase of depth of crack, the crack tip stress value will increase sharply, then when the crack depth is larger than 5.5 mm,the bridge shell will have the risk of fracture.(4) According to the crack defects influence on the stress distribution, proposing two repair plans in view of the dangerous section of the fatigue crack defect- reduce the stress concentration and change the material. Reduce stress concentration method is applicable to fatigue crack depth is less than lmm of drive axle housing, a simple way for repair. After the repair of drive axle housing,it can reach a fatigue life design standard; The another method is to change material, it can repair the axle housing and achieve the quality of the new product, but the repair process is relatively complicated, and require welding residual tensile stress is less than 462.4 MPa. |
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