MACHINE TOOL VIBRATIONS
Machine tools experience both forced and self-excited vibrations during machining operations. The cutting forces can be periodic, as in the case of milling. The nonsymmetric teeth in drilling, unbalance, or shaft runout in turning and boring can also produce periodically varying cutting forces. In all cases, the cutting forces can be periodic at tooth- or spindle-passing frequencies, which may have strong harmonics up to four to five times the tooth- or spindle-passing frequencies. If any of the harmonics coincide with one of the natural frequencies of the machine and/or workpiece structure, ...