The steel plate curvature analytic modeling for the snake rolling with the same roll diameters

Abstract

The snake rolling can keep the plate shape well, and the larger shear strain produced by the snake rolling is conducive to the deformation penetrating into the center of the heavy plate. So it provides a new method for producing the high-performance heavy steel plate. However, there is little research on the plate curvature modeling which is the key to achieve the snake rolling process. The deformation region was divided into four different zones at most which was depended on the positions of the two neutral points, and this number could be dropped to three or two in some other conditions. It was divided into three different cases according to the neutral point position: I, II, III and IV; I, II and IV; II and IV. The unit pressure and the accumulated shear strain deviation between the top and bottom portions of the plate with every case were established, and the plate curvature caused by shear strain was calculated on this basis. The plate curvature caused by the axial strain was also calculated according to the flow criterion. The approximations are corrected by a fitting coefficient E. The homogeneity coefficient E was introduced during the plate curvature modeling process to make the model more accurate. Then the total plate curvature model was established. The simulation of snake rolling process is carried out by using ANSYS LS-DYNA, and the plate curvature results are compared with the theoretical method. The results showed that the maximum and minimum relative error of the model was 11.61% and 0.28% compared to the simulation method, which can be applied for the online plate curvature control application with the effect of some self-learning methods. The plate curvature affecting law with the different process parameters (roll offset, roll speed ratio, rolling reduction, plate thickness and so on) was obtained in this paper. The research about the plate curvature modeling will provide important references for the heavy steel plate snake rolling production.