Regenerative effect in rolling chatter

The regenerative effect has been extensively studied in the field of metal cutting and recognized as one of the major causes of self-excited vibrations commonly known as chatter. In the presence of interactions between rolling mill stands, affecting the overall system dynamics, it will be shown that a tandem rolling mill may also become unstable due to a similar regenerative mechanism even though the individual stands are stable. In this paper, tandem mill stability will be investigated, in terms of the regenerative effect, using a multistand chatter model that incorporates a homogeneous process model and a mill structural dynamics model. Finally, simulation results will be presented to demonstrate the effects of regeneration on a three-stand tandem mill.