Dynamic modeling and numerical analysis of a cold rolling mill

Abstract

The dynamic characteristics in a rolling process have been investigated with various methods, but a mathematical model to predict actual chatter vibration has not been established. In this paper, we propose a mathematical model of a cold rolling mill to predict chatter vibration. The mathematical model was verified by experiment and theoretical analysis. The chatter frequency predicted by the model was very similar to that determined by experiment and theoretical analysis. The model took into account the stiffness caused by roller bearings and contact between rolls. We considered not only the vertical, but also the horizontal rolling force, with the aim of investigating the added effect of the latter. The work and the intermediate rolls had the same periods of vibration because their masses were similar and the rolls were adjacent. Both the vertical and horizontal vibrations were investigated. The maximum displacement and amplitude of chatter frequency were much larger in the vertical than in the horizontal direction. To reduce chatter vibration, the rolling force had to be reduced within the range of efficient productivity. The chatter frequency that affected the performance of the rolling mill was found, and the dynamic characteristics were investigated.