Experimental investigation of the gyroscopic and rotary inertia effects on the chatter boundary in a milling process

Experimental examination of the gyroscopic and rotary inertia effects on the chatter boundary in a milling operation is the chief aim of this article. The equations of motion of the tool vibration are derived based on Timoshenko beam theory and Hamilton principle by considering gyroscopic moment, rotary inertia, velocity-dependent process damping and radial immersion effect. For a range of depth of cuts and spindle velocities, the stability of the milling process is determined by using the method of multiple scales and creating a so-called stability lobe diagram (SLD) in which boundaries separate stable area and unstable or chatter area. Then the newly obtained SLD with the effects of rotary inertia and gyroscopic moments is verified experimentally. Indeed, the verification of the lobes at the speeds where the distinction is sound between the conventional lobes and the newly obtained lobes is presented. Here, the SLD obtained without the effects of rotary inertia and gyroscopic moments is so-called conventional SLD. For this purpose, some experiments are conducted to demonstrate the progressive move into the unstable zone at the locally optimum point of SLD. Finally, a parametric study is presented as a validation of the newly obtained lobes from the sense that the effects of different parameters on these limits are as expected.

Keywords:

Experimental Investigation , rotary inertia and gyroscopic moments , chatter , Milling , Timoshenko beam theory , Stability lobe diagram