3D FEM analysis of strip shape during multi-pass rolling in a 6-high CVC cold rolling mill

A 3D elastic-plastic finite element method (FEM) model of cold strip rolling for 6-high continuous variable crown (CVC) control rolling mill was developed. This model considers the boundary conditions such as accurate CVC curves, total rolling forces, total bending forces and roll shifting values. The rolling force distributions were obtained by the internal iteration processes instead of being treated as model boundary conditions. The calculated error has been significantly reduced by the developed model. Based on the rolling schedule data from a 1,850-mm CVC cold rolling mill, the absolute error between the simulated results and the actual values is obtained to be less than 10 mu m and relative error is less than 1 %. The simulated results are in good agreement with the measured data. The developed model is significant in investigating the flatness control capability of the 6-high CVC cold rolling mill in terms of work roll bending forces, intermediate roll bending forces and intermediate roll shifting values.