SUPPRESSION OF PERIOD DOUBLING CHATTER IN HIGH-SPEED MILLING BY SPINDLE SPEED VARIATION

Abstract

Spindle speed variation is a well known technique to suppress regenerative machine tool vibrations, but it is usually considered to be effective only for low spindle speeds. In the current paper, spindle speed variation is applied to the high speed milling process, at the spindle speeds where the constant speed cutting results in period doubling chatter. The stability analysis of triangular and sinusoidal shape variations is made numerically with the semi-discretization method. It is shown that the milling process can be stabilized by increasing the amplitude of the spindle speed variation, while the frequency of the variation has no significant effect on the dynamic behaviour. The results are validated by experiments. Based on the analysis of the machined workpieces, it is shown that the surface roughness can also be decreased by the spindle speed variation technique.

Keywords:

• chatter
• milling
• period doubling
• spindle speed variation
• stability
• surface roughness

ACKNOWLEDGMENTS

This work was partly supported by the European Union Interreg IIIa AEROSFIN, by the Midi-Pyrénées Region Project “Complex workpiece machining in aeronautical context”, and by the János Bolyai Research Scholarship of the HAS and by the HSNF under grant no. OTKA K72911. The authors would also like to thank Vincent WAGNER for his help on data processing.

Notes

*Sadly, Grégoire Peigné died during the preparation of the article.