Abstract: Accurate prediction of cutting force is essential for optimizing milling process parameters and improving efficiency. In five-axis machining, the efficient computation of cutter-workpiece engagement (CWE) for different cutter remains challenge in the prediction of cutting force. An efficient computation method for the CWE of a general cutter in five-axis machining, based on distance fields and adaptive octrees, is proposed. The method involves initializing and storing the workpiece surface using distance field and octree techniques, as well as constructing a surface distance function for the general cutter. Then, an equivalent motion method for calculating the workpiece surface after material removal is introduced, eliminating the need to calculate the cutter swept volume, which significantly improves the efficiency of material removal simulations. Furthermore, the extraction of tool-workpiece contact region facets is established based on the distance function, using the STL slicing method to obtain boundary points on the cutter elements, followed by determining the entry and exit angles. Instantaneous cutting forces are computed based on a mechanical force model. The integrated functionalities of material removal simulation and cutting force prediction are implemented in the self-developed CNC machining simulation and optimization software, TurboCut. The simulation results are shown to have advantages when compared with those obtained using ModuleWorks or the B-rep method. Validation against cutting test is demonstrated to show that the proposed method achieves efficient CWE computation and cutting force prediction.

Key words: general tool, five-axis milling, cutter-workpiece engagement, cutting force prediction