圆柱齿轮淬火计算机模拟的研究.pdf

内蒙古科技大学硕士学位论文- 1 - 摘要淬火是实现零件组织结构变化的一个重要手段。随着计算机技术的发展,淬火过程的计算机模拟成为研究在这一过程中零件温度场、应力场相互作用、相互影响、相互耦合的有效方法。本文基于传热学基本原理,热弹塑性理论,采用有限元分析软件 ANSYS ,对材料为 20CrMnTi 的渐开线圆柱直齿内齿轮的淬火冷却过程进行了计算机模拟计算。为了实现研究的目标,首先用 APDL 编制了创建内齿轮模拟几何模型的程序,实现了齿轮参数化建模。所编制的绘制渐开线圆柱齿轮的命令流程序适用于类似的齿轮,以后绘制类似的齿轮时,只需修改其中的某些参数即可。其次在淬火温度场的模拟中,考虑了内齿轮材料的热物性参数和淬火介质换热系数的非线性,包含了相变潜热与温度场的耦合计算,为进一步研究应力场打下了基础。在对应力场的模拟中,运用增量理论及相应的弹塑性本构方程,并假设材料的塑性区满足 Prandtl-Reuss 塑性流动法则,考虑了材料非线性和温度、相变对应力的影响,并对淬火后内齿轮的变形进行了验证。在模拟中为了提高模拟精度及节省计算时间,采用了表面换热系数函数加载、内齿轮局部网格细化和变时间步长等方法。通过模拟计算,模拟和研究了淬火过程中温度、位移、应力随时间的变化情况,并得出了相应结论。本文所作的工作为进一步研究淬火过程中的数学模型,实现淬火过程控制建立了基础。关键词: 淬火; ANSYS ; 计算机模拟; 温度场;应力场内蒙古科技大学硕士学位论文- 2 - Abstract Quenching is an important met hod of optimizing the structure of the parts. With the development puter te chnology, puter simula tion of quenching process has e the effective method in st udying the intercoupli ng and interacting of the fields between temperature and stress. Based on both the principle of he at transfer and the theory of thermo-elasto- plasticity, the quenching cooling process of 20CrM nTi cylindrical involute internal spur gear was simulated with the help of large-scale finite element software ANSYS. In order to achieve the study aim, firstly the simulation mode l of the internal spur gear is created. For the simulation of temperature, the non-linearity of bo th the thermophysical property parameters and the co nvection heat transfer coefficient is take n into account, and the intercoupling of both the phase tr ansformation and the temperature is also into consideration. This is a base for further study ing the fields of the stress. Th e program of creating 3-D finite element model of the internal spur gear is programmed by using APDL and the program can be, easily and conveniently, applied to create similar cylindr ical involute spur gears by only modifying some parameters in program. The simulation of stress is made with help of ANSYS, ba sed on incremental theory and corresponding