Application of numerical simulation technology in gear precision forging

Metal bulk forming is a complex process of large plastic deformation, that is, there is a nonlinear relationship between the nonlinear stress and strain of the material in the state of plastic deformation, there is a nonlinear relationship between the geometric nonlinear strain and displacement caused by large deformation, coupled with the nonlinear boundary conditions, it is very difficult to accurately solve the problem of bulk forming. In the past, people mostly used approximate numerical analysis methods, such as principal stress method, slip line method, energy method, one method and general solution, which need to make more simplification and assumptions, so that the analysis results are far from the actual situation. When solving slightly complex problems, it can not meet the needs of theoretical analysis and engineering practice, and it is rarely used in metal plastic forming analysis at present. With the development of plastic finite element theory and computer technology, the application of finite element numerical simulation in metal plastic forming analysis has been paid more and more attention.

The analysis of metal forming by finite element method has the following advantages: it is suitable for the analysis of all kinds of metal forming processes, and can provide a wealth of element types without the limitation of specific forming problems, so it has a high boundary fitting and precision, and it also makes the analysis of complex forming processes possible to comprehensively consider the influence of various factors on the forming process, For example, temperature, friction and lubrication conditions, material characteristics, deformation speed and die geometry can provide similar deformation mechanics information under the premise of few assumptions, such as the distribution of stress, strain and temperature field, metal plastic flow law, forming load and other force parameters, which can optimize and control the process.

Gear geometry is complex, product size accuracy, surface quality, structure and mechanical properties are strict. It is difficult to form, complex filling process, poor material fluidity, many influencing factors, large forming load, product quality and die life are not easy to guarantee, which seriously affects the practical process. Using the method of test to analyze the process of gear precision forging, because of die material, precision machining and equipment capacity requirements, etc., it is expensive and the workload is huge, and physical simulation and test analysis have limitations. It is difficult to use the traditional mechanical analysis method for this kind of complex forming process, so it is very necessary to carry out the numerical simulation analysis for the gear precision forging process.