Primary chatter is investigated experimentally using both traditional
and frequency domain techniques. The experiment was conducted on a CNC
lathe using coated carbide cutting inserts. The tool vibrations and c
utting forces were measured and analyzed for different sets of cutting
conditions. The experimental results indicated that the tool vibratio
ns are more sensitive to the cutting geometry than the cutting forces.
Also, the feed rate was found to be the most critical parameter which
leads the system into chaotic behavior. In particular, the wavelet tr
ansform technique was used to analyze chatter signals. It clearly iden
tified the transient boundary and the occurrence of the built-up edge
(BUE). Based on the frequency information contained in the wavelet tra
nsforms, the cutting process is probably quadratically non-linear. In
addition, for high feed rate, chaotic behavior was observed. Tradition
al techniques were also used to study the chaotic behavior of the proc
ess. These techniques include phase plane, power spectra, Poincare map
and fractal dimensions. They all agreed with the observation obtained
by the wavelet transform regarding chaotic motion.