Fully coupled fluid-structure-contact simulations to understand the processes in the contact zones during lubricated orthogonal cutting

• Applicants: Professorin Dr.-Ing. Stefanie Elgeti; Professor Dr.-Ing. Andreas Zabel
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 439919057

In metal-cutting manufacturing, a particularly large sustainability potential can be found in reducing the consumption of cooling lubricants (CL), which cause damage to the environment and health as well as high costs. In order to maintain productivity and ensure the required component quality despite the reduction in coolant quantities, the use of coolant must be more targeted in the future. In particular, there is great potential in exploiting the tribological effect of the coolants. In order to utilize this in machining production, the underlying mechanisms of action must be understood in detail and taken into account in digital tools for process and tool development and their optimization.In the context of this follow up project in the framework of the priority project SPP 2231, developments for the improvement of friction modeling under consideration of a CL for numerical chip formation simulations will be performed for this purpose. This is achieved by coupling a microscopic tribology model with a macroscopic chip formation model and offers the possibility to model the friction in the chip formation zone as a function of temperature, relative speed, contact normal stress as well as surface topographies of the tribo-partners and an intermediate medium. In order to gain the technological understanding and the data for the modeling and to lay a basis for the later transfer to industrial production, additional basic investigations on the tribological behavior of the chip formation zone are planned. In the first phase of the project, experimental investigations of the working mechanisms of cooling lubricants were carried out and it has been succeeded to develop a micro-tribological model of the chip formation zone, which should make it possible to investigate these mechanisms on an experimentally inaccessible scale and make them usable for chip formation simulations. The micro-model is based on a fluid-structure contact simulation using spline-based finite element methods. In the next project phase, the coupling of the micro-tribological model with a chip formation model is planned. This coupling will allow to model the friction behavior in the numerical chip formation simulation locally graded considering a CL. To be able to achieve this goal, in-depth experimental investigations with the objectives of influence analysis and simulation validation are necessary. In addition to the application of a method for the visualization of the coolant distribution in the chip formation zone, these include in particular the characterization of the sticking and sliding zone as well as the determination of the local mechanical loads during machining. Finally, in preparation for the third funding phase, the experimental framework shall be transferred to a turning process.

• DFG Programme: Priority Programmes
• Subproject of: SPP 2231: Efficient cooling, lubrication and transportation – coupled mechanical and fluid-dynamical simulation methods for efficient production processes (FLUSIMPRO)
• International Connection: Austria