STABILITY IN VARIABLE-PITCH MILLING REGARDING REGENERATIVE CHATTER

摘要

The regenerative chatter in milling process is studied for two different variable-pitch cutters one with (a) four flutes and the other with (b) six flutes. The cutting dynamics of the process is evaluated from stability perspective. Mathematically, the problem is recognized in a general class of delay differential equations (DDE) with multiple delays, whose stability can be analyzed by a recent stability analysis methodology called the Cluster Treatment of Characteristic Roots, CTCR. This method proves to be very beneficial to surface two critical aspects of the process, which maintain chatter-free cutting: (ⅰ) the pitch angle geometry of the cutting tool and (ⅱ) admissible cutting conditions to determine the depth-of-cut and the spindle speeds. Case studies are provided to demonstrate the capabilities.