Most of the steady state grinding force models for cylindrical grinding show a dependence on the rotational speeds of both the workpiece and the grinding wheel. If, due to the flexibility of the workpiece drive, a torsional oscillation was superimposed on the mean rotational speed of the workpiece, then according to the cutting force models the cutting forces would vary about their mean. Any variation in the magnitude and/or phase of the cutting forces must have an influence on the chatter performance of the machine. Mathematical models are used to predict that such would be the case when the natural frequencies of the machine tool structure and the workpiece drive (torsion) are close. An experimental programme undertaken to test the idea is described. An artificially flexible workpiece drive was arranged and the chatter of the machine monitored. It was found that the torsional flexibility prevented 'workpiece' chatter from arising and, under certain conditions, grinding wheel' chatter was suppressed. The paper briefly outlines the hypothesis, describes the experimental arrangement and presents the results showing the beneficial effects. Some practical applications are provided.
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