Abstract: Accurate shape control theory is of great significance to improve the quality of strip rolling. At the same time, the efficient prediction of roll gap becomes an important part of the shape control theory. Aiming at the problem of online computation of roll gap in a complex roll system, this paper presents a new and efficient calculation method to predict the roll gap numerically. The method is based on the influence function method which is widely used in simple roll systems, and combined also with the idea of establishing stiffness matrix like that used in finite element method. The matrix can be solved by matrix iteration so as to predict the roll gap. Through the pre-processing of the contact pressure vector Ψ between rolls, the efficient presupposition of an initial value may be realized. Therefore, the efficiency and accuracy of the new prediction method are further improved. By comparing the proposed prediction method with the finite element method, it is found that the calculation time of this method is much less than that of the finite element method, while the accuracy approaches greatly to that of the finite element method. The maximum error resulting from this method is only 1.6%, which meets requirements of the on-line calculation indeed.

Key words: roll mill 20, roll deformation, influence function method, finite element method, initial value preset