Thermomechanical modelling of oblique cutting and experimental validation
Thermomechanical modelling of oblique cutting and experimental validation
复制标题
DOI：
10.1016/j.ijmachtools.2004.01.018
复制
发表时间：
2004-07-01
影响因子：
14
通讯作者：
Molinari, A
中科院分区：
文献类型：
--
作者：
Moufki, A;Devillez, A;Molinari, A
采用解析方法建立了斜角切削过程的数学模型。考虑了应变速率敏感性、应变硬化和热软化等材料特性。切屑的形成被认为主要是通过在一个称为主剪切带的薄带内的剪切而发生的。分析仅限于固定流和材料流内的主要剪切区建模通过使用一维的方法。热力耦合和惯性效应占。切屑流动角是通过假设刀具工作面上的摩擦力与切屑流动方向共线来确定的。在切屑-刀具界面处，摩擦条件可以受到由大的压力和滑动速度值引起的重要加热的影响。尽管机械加工中的摩擦定律的现象很复杂，但一个合理的假设是，平均摩擦系数主要是工具-切屑界面处的平均温度的函数。模型预测和实验结果之间的比较进行不同的值的切削速度，未变形的芯片厚度，正常的切削角和倾角。一个关键的研究，以显示该模型的输入参数，包括法向剪切角，主剪切区的厚度和刀-屑界面的压力分布的影响。该模型允许预测的切削力，切屑流动方向，切屑和刀具之间的接触长度和温度分布的工具-切屑界面上的刀具磨损有重要影响。(C)2004 Elsevier Ltd.保留所有权利。
An analytical approach is used to model oblique cutting process. The material characteristics such as strain rate sensitivity, strain hardening and thermal softening are considered. The chip formation is supposed to occur mainly by shearing within a thin band called primary shear zone. The analysis is limited to stationary flow and the material flow within the primary shear zone is modelled by using a one-dimensional approach. Thermomechanical coupling and inertia effects are accounted for. The chip flow angle is determined by the assumption that the friction force on the tool face is collinear to the chip flow direction. At the chip-tool interface, the friction condition can be affected by the important heating induced by the large values of pressure and sliding velocity. In spite of the complexity of phenomena governing the friction law in machining, a reasonable assumption is to consider that the mean friction coefficient is primarily function of the average temperature at the tool-chip interface. Comparisons between model predictions and experimental results are performed for different values of cutting speed, undeformed chip thickness, normal cutting angle and inclination angle. A critical study is presented in order to show the influences of the input parameters of the model including the normal shear angle, the thickness of the primary shear zone and the pressure distribution at the tool-chip interface. The model permits to predict the cutting forces, the chip flow direction, the contact length between the chip and the tool and the temperature distribution at the tool-chip interface which has an important effect on tool wear. (C) 2004 Elsevier Ltd. All rights reserved.