Analytical prediction of chatter stability for modulated turning
Analytical prediction of chatter stability for modulated turning
复制标题
DOI：
10.1016/j.ijmachtools.2021.103739
复制
发表时间：
2021-05-13
影响因子：
14
通讯作者：
Shamoto, Eiji
中科院分区：
文献类型：
--
作者：
Nam, Soohyun;Eren, Bora;Shamoto, Eiji
本文提出了低频振动辅助车削过程（即调制车削）的分析颤振稳定性预测。最初提出在加工中引入低频刀具调制，将连续切削过程转变为离散切削过程，从而消除切屑缠绕/堵塞。然而，工具调制辅助对颤振稳定性具有根本性影响。本文是首次尝试通过频域分析来揭示调制转动过程的再生颤振稳定性。对刀具啮合运动学和动态切屑生成机制进行了建模。据了解，与传统车削或铣削工艺不同，调制车削工艺由于 1) 短时间刀具啮合和 2) 多个再生循环而表现出明显的稳定效果，因为动态切屑厚度受到过去两次旋转的影响。考虑刀具的平均浸入度（切削占空比），提出了该过程的零阶频域颤振稳定性模型。开发的模型用于量化多延迟再生和工具调制参数对稳定环形成的影响。分析稳定性解决方案以时域数字仿真结果为基准，并且两种预测都通过正交切割实验进行了验证。结果表明，所提出的解决方案可以准确生成典型调制条件下调制转向的稳定性波瓣图（SLD）。
This paper proposes an analytical chatter stability prediction for low frequency vibration assisted turning process, i.e. the modulated turning. Introducing low frequency tool modulations in machining is initially proposed to transform continuous cutting process into a discrete one so that chip-entanglement/jam could be eliminated. However, tool modulation assistance has a fundamental effect on chatter stability. This paper is the first attempt to uncover the regenerative chatter stability of the modulated turning process by a frequency-domain analysis. Tool engagement kinematics and the dynamic chip generation mechanism are modeled. It is understood that unlike conventional turning or milling processes, modulated turning process exhibits distinct stabilizing effects due to 1) short-time tool engagement and 2) multiple regenerative loops as the dynamic chip thickness is affected by past two revolutions. Considering the average immersion of the cutting tool (cutting duty cycle), a zero-th order frequency domain chatter stability model for the process is proposed. The developed model is used to quantify the effect of multi-delay regeneration and tool modulation parameters on the stability loop formation. The analytical stability solutions are benchmarked against the time domain digital simulation results, and both predictions are validated through orthogonal cutting experiments. It is shown that the proposed solution can accurately generate the Stability Lobe Diagram (SLD) of modulated turning for typical modulation conditions.