Countermeasure against chatter in end milling operations using multiple dynamic absorbers

The present study investigates the effect of multiple dynamic absorbers on chatter generated in the end milling operations by performing stability analysis and a cutting test. The dynamic absorbers proposed in the present paper are attached to a collet chuck in order to suppress tool chatter caused by the bending vibration of the tool and spindle system. The dynamic milling model is considered to have two orthogonal degrees of freedom. The dynamic absorbers, which have identical mass, damping ratio, and natural frequency, are assumed to have a single degree of freedom that rotates with a tool and spindle system. In the present paper, stability analyses are performed by means of complex eigenvalue analysis for each angular immersion of the cutting edge in order to investigate the effect of the dynamic absorbers on the stability of the dynamic milling model. The optimal natural frequency and damping ratio of the dynamic absorbers to maximize the chatter-free axial depth of cut are shown to vary with spindle speed. Furthermore, the effect of the dynamic absorbers on chatter is validated by a cutting test, and the experimental results are confirmed to agree qualitatively with the analytical results.