General Milling Stability Model for Cylindrical Tools

In this study, the stability properties of general milling processes are summarized and compared to each other considering different special tool geometries. This general model can deal with any kind of flute geometry and with non-proportional damping using the semi-discretization method. A real-case experimental tip2tip modal analysis of a carbide milling tool is taken, which serves as the reference dynamics for the stability calculations. A fitting algorithm is used to extract the modal parameters of the corresponding non-proportionally damped system that is given directly in first order representation. The asymptotic stability of the stationary solution of the resulting time-periodic parametrically excited and time-delayed system is investigated by the semi-discretization algorithm. The stability properties of variable pitch, serrated and variable helix tools are compared with the one of the conventional helical tool.