Hybrid Calculations of Bending Deformations for 20 Roll Cold Rolling Mill

In multi-high mills, the slim fixed floating work rolls are supported by primary and secondary intermediate rolls and several supporting rolls mounted pairs-wise on supporting shafts. Over the eccentric adjustment of saddle assemblies and hydraulic adjustment device the roll gap adjusts the specific elastic bending deformation of the support system. Based on a hybrid calculation model the influence and limits of an active adjustment device for 20 roll mill will be presented. Thereby the bending deformations as well as the contact deformations of the complete system including the forming process in settings of the elementary plasticity theory (EPT) will be considered.The modeling of the bending deformations of the roll systems are based on FE-Beam elements. The flattening in the contact zone between the rolls will be formulated by a modified non-linear approach, according to Hertz-Johnson. The contact of the deformed zone is aligned in the discretized EPT-roll model by Alexander with Hitchcock-flattening. The iterative analysis of the compact models leads to “force-deformation-relations”, which provides the influence of the variation of the gap. The force-deformation-relations will be detailed discussed in parameter studies of a real 20 roll mill.