Machine Tool dynamics is evaluated under actual working conditions by using Dynamic Data System methodology.
Variation of cutting dynamics in a lathe is investigated with changing three cutting conditions, viz. feed rate, spindle speed and depth of cut. A long slender bar is used as a workpiece and longitudinal turning operation is performed. Chattering phenomenon which has detrimental effects on the surface of the work piece is also examined.
Change in cutting dynamics is evaluated when the cutter moves along the workpiece. The accelation signals measured from the tailstock and the toolpost are compared with the thrust force from the tool dynamometer when chatter occurs. The sensitivity analysis of the tailstock and toolpost vibrations to the onset of chatter is performed.
Three signals spontaneously have similar power spectral densities when chatter occurs. It shows that two acceleration signals will be good alternatives of the thrust force when tool-dynamometer set up is not available.
PSD analysis of the thrust force signals according to the cutting position shows that machine tool system stability is increased as the cutter moves far from the center of the workpiece.
