Modeling topographical variations of cutting edges to consider the stochastic behavior of tool wear in milling simulations

For the analysis of machining processes, simulation systems can be used to investigate characteristics such as process forces or the resulting workpiece quality. A significant factor influencing the prediction quality is the accuracy of the tool models, which have to adequately represent the shape of the tools used in the process. These tools are subject to various wear-related shape changes over the duration of the tool life. The explicit representation of cutting edges within process simulations is particularly suitable for modeling these shape changes of the tool during the process in sufficient detail. However, it is challenging to explicitly map the different scales of variations, especially due to the large number of different shapes and localizations of tool wear along the cutting edge. In order to represent the topographical changes over the tool lifetime in a model, a characterization of different wear types is necessary. For this purpose, the wear behavior was characterized for different tool-material combinations using a geometric analysis, which allows a differentiated representation of abrasive, adhesive and crater wear. These characterizations are used to synthesize tool models using a methodology in which stochastically distributed wear phenomena are allocated on the cutting edge for different tool lifetimes. These derived explicit tool models are used in a time step-based simulation system to predict the wear-specific variations of the occurring chip thicknesses.