Prediction of Surface Quality due to Chatter Vibration in Rolling of Thin Steel Strip Using ALE Finite Element Method

Abstract

Chatter is one of the most encountered vibration problems in high-speed rolling of thin steel sheets in tandem mills. Due to its negative cause on product quality and maintenance costs, chatter is a technical and economical problem in rolling mills. To study chatter in rolling, it is necessary to set up models for the rolling process as well as the mill stand. Existing models of rolling process are analytic and are based on many simplifying assumptions. In current work the finite element method is utilized for the first time to model the chatter vibrations in rolling, which relaxes many of these assumptions. The model has the benefit of mass translation to the computational region by using Arbitrary Lagrangian Eulerian (ALE) technique, which tremendously reduces huge computational requirements of common Lagrangian models. Four chatter mechanisms in rolling are reviewed in this paper, but the presented model is updated for simulating the negative damping effect by means of some online velocity sensors and signal filtering method in applying the ALE boundary conditions. Using this new model, single stand negative damping mechanism of chatter and its effect on the sheet surface is understood more accurately. Simulation results are in comprehensive agreement with the experimental and industrial observations.