Multi-scale modeling of the thermal workpiece load in the turning process considering the cutting fluid

考虑切削液的车削过程中工件热载荷的多尺度建模

• 批准号: 439919433
• 负责人: Professor Dr.-Ing. Thomas Bergs
• 金额: --
• 依托单位: Werkzeugmaschinenlabor - WZL
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/439919433?language=en
• 关键词: Multi; scale; modeling; thermal; workpiece

The use of cutting fluid is beneficial in the machining technology in order to transport the process heat generated from the tool-workpiece interface and to reduce the frictional heat due to its lubricating effect. The thermo-mechanical load induced in this context has a considerable influence on the surface integrity and the associated functionality of the component. However, the thermal and mechanical load of the workpiece has been modeled separately in previous work. For a comprehensive understanding of the process, the investigation of the interaction between mechanical and thermal phenomena is necessary. Therefore, the main objective of the proposed research project is the multi-scale modeling of the thermal workpiece load in the turning process, considering the supply of cutting fluid and the tool wear condition. In the first funding period, a coupling approach between Computational Fluid Dynamics (CFD) and Finite Element Method (FEM) is developed. The coupling approach is based on the iterative exchange of mechanical and thermal parameters between FEM and CFD. Based on FEM simulations and experiments, the chip geometry is calculated and used as the input for CFD mesh generation. In the CFD simulation, the heat transfer coefficients are then quantified and transferred to the FEM simulation, which then calculates the modified chip geometry. In addition, further sub-models are developed and validated for the description of the friction behavior as well as the contact heat transfer under consideration of cutting fluid. Overall, this iterative coupling approach can be used to determine the temperature distribution and gradients in the boundary layer of complex components during machining. By enhancing the FEM chip formation simulation to the actual tribological conditions considering friction and heat transfer models, a major scientific gap in modeling approaches is closed, and thus a comprehensive virtual image of the machining process under real conditions can be achieved.

切削液的使用有利于机械加工技术，可以传输刀具与工件界面产生的加工热量，并因其润滑作用而减少摩擦热。在这种情况下引起的热机械负载对部件的表面完整性和相关功能具有相当大的影响。然而，在之前的工作中，工件的热载荷和机械载荷已分别建模。为了全面了解该过程，有必要研究机械和热现象之间的相互作用。因此，本研究项目的主要目标是考虑切削液的供应和刀具磨损条件，对车削过程中工件热载荷进行多尺度建模。在第一个资助期间，开发了计算流体动力学（CFD）和有限元法（FEM）之间的耦合方法。耦合方法基于 FEM 和 CFD 之间机械和热参数的迭代交换。基于 FEM 模拟和实验，计算芯片几何形状并将其用作 CFD 网格生成的输入。在 CFD 模拟中，传热系数被量化并转移到 FEM 模拟，然后计算修改后的芯片几何形状。此外，还开发并验证了进一步的子模型，用于描述摩擦行为以及考虑切削液的接触传热。总体而言，这种迭代耦合方法可用于确定加工过程中复杂部件边界层的温度分布和梯度。通过将有限元切屑形成模拟增强到考虑摩擦和传热模型的实际摩擦条件，可以弥补建模方法中的主要科学差距，从而可以实现真实条件下加工过程的全面虚拟图像。