【作者】 张华；

【导师】 王珉； 左敦稳；

【作者基本信息】 南京航空航天大学 ， 机械制造及其自动化， 2004， 硕士

【摘要】 本文在研究了金属切削原理和有限元理论的基础上，借鉴前人在二维切削仿真研究中的成果与结论，选择了基于等效塑性应变的切屑分离准则，建立了有限元分析模型，利用商业化的有限元分析软件进行了求解运算，动态模拟了三维状态的金属切削过程。本文具体研究内容如下： 1、建立了二维切削加工有限元分析模型，进行了仿真实验。对金属切削过程中应力场、应变场的变化及其规律作了定性分析。给出了应力、应变等值线图，观察了切削过程中各主要变形区位置和剪切带形成过程。仿真结果验证了随刀具前角增大，剪切角相应增大。 2、建立了斜角切削加工有限元分析模型，进行了仿真实验。通过提取切屑模型的关键线进行测量，得到了切削过程中切屑流屑角、上卷半径和侧卷半径的数值；验证了流屑角和刀具刃倾角总是近似相等的斯坦布勒实验法则；并实现了利用有限元仿真对切屑形态与受阻运动趋势的预测。 3、建立了三维切削加工有限元分析模型，进行了仿真实验。研究了切削力变化规律和切屑成形过程。仿真得到了不同切削用量下的切削力数值，为切削工艺研究及刀具设计提供了有用数据。通过和切削试验结果进行对比分析，验证了仿真结果的准确性，证明了仿真模型的有效性。 4、为了将该仿真模型应用于刀具断屑槽形的设计与优化，本文通过改变全圆弧槽形刀具几何参数进行了一系列仿真实验，完成了对该种槽形流屑、卷屑性能的定性研究，得到了一些有意义的结论。 5、开发了金属切削过程仿真分析的集成软件。工艺人员通过软件友好的人机界面，可以完成相应条件下的程序编写，计算分析，数据处理及结果演示。软件操作方便，运行可靠。更多还原

【Abstract】 A Lagrangian finite element model of three dimensional machining is developed to simulate the metal cutting process in this thesis, among which a chip-separation criterion based on the failure character of the material model is the most important. The simulation is performed with a general international finite element-based modeling software. The main work in this thesis can be concluded as follows.1 .The orthogonal cutting model is validated against the state of stress and strain, the form of shear plane and the effect of the tool rake angle on the angle of shear plane.2.The obique cutting model is validated against the relation between the chip flow angle and the tool inclination angle, upward chip curling and sideward chip curling. Therefore, the geometric shapes and the movement of the chip can be predicted accurately.3.The three dimensional cutting model is validated against predictions of cutting forces and chip formation under several cutting conditions. Comparisons of predictions are made against test data to further verify the feasibility of the model.4.1n order to design and optimize the geometry parameters of the chip breaker, some cutting simulations under a variety of parameters are carried through to investigate the effect of the breaker on the geometric shapes of the chip.5.The integrated software is developed to analyze the cutting forces and chip formation. Using the software, the simulation programs are automatically set up, and the cutting forces and chip formation under different machining conditions can be computed expediently.更多还原