CAD/CAM systems for multi-axis milling typically base manufacturing operations on geometric constraints, without considering physical influences such as cutting forces and temperatures in the cutting zone. Furthermore, the processes in industrial practice are typically based on experience and designed iteratively.
This approach is imprecise, time-consuming, and costly. In addition, by not adequately considering the forces and temperatures that occur during the process, decisions can lead to increased tool wear or damage to the workpiece. What is needed is a solution that combines the strengths of geometric and physical modeling methods.
The goal of the research project "FEMmeetsDR" is to successfully integrate the modeling approaches of geometric intersection calculation and the Finite Element Method (FEM) into a physical process simulation. In order to make the process design knowledge-based, the virtual manufacturing environment of CAM planning will be extended. The FE simulations are performed in advance. Subsequently, the FE simulations or their results are transferred to the application level of CAM process design, which involves thousands of tool path points and variable engagement conditions, using the intersection calculation based on orthogonal individual cuts.
By integrating the physical process simulation into the CAM system for 5-axis milling toolpath design, process design becomes more time-efficient and accurate. Critical machining areas can be identified prior to manufacturing, process ramp-ups are shortened, and post-processing efforts are reduced, thereby improving part quality in the context of the manufacturing cost/quality trade-off.
In the first phase of the project, the project team will extend a geometric intersection calculation simulation developed at Fraunhofer IPT to enable the representation of relevant engagement conditions and the accurate generation of chip sizes. In parallel, the project partners will calibrate an FEM simulation to establish an FE database based on various process state variables. Additionally, generator modules will be developed to generate digital tool models that can be implemented in the process simulation software.
In the second phase of the project, the actual coupling of the simulations will be developed. The project team will evaluate and implement a suitable interface that enables efficient access to the FE database during the intersection calculation. This will allow the calculation of forces occurring in the process using both empirical models and FEM.
Furthermore, a parameterization algorithm will be developed to transfer the calculations from the coupled simulation to other tool geometries, making them available for further processes.
The methodology will be verified in several steps. Initially, a pure FEM modeling of a milling tool will be compared with modeling using coupled FEM-DR simulation and empirical measurements to validate the two modeling strategies. Subsequently, two demonstrator components will be manufactured. One demonstrator will be manufactured using CAM programming based on experience-based process parameters, while the other will be manufactured using process parameters optimized by the coupled simulation. During the process, cutting force components and axis positions will be continuously recorded to visualize the forces on the demonstrator, identify critical areas, and evaluate the simulated process design compared to the measured forces.
The research project "FEMmeetsDR - Multi-scale modeling of multi-axis milling process by linking finite element simulation with geometric intersection calculation" is funded by the Federal Ministry for Economic Affairs and Climate Action (BMWi) under the funding program "IGF - Industrial Collective Research".
Funding code: 22305N
AiF - Industrial Research Network for Small and Medium-sized Enterprises