Abstract: Studies on chatter, as the consequence of the interaction between the structural dynamics of the mills and the dynamics of the rolling process, depend on appropriate structural models, as well as on accurate description of rolling process. Existing models of a mill structure are summarized, including three typical vibration models(the third-octave-mode, the fifth-octave-mode or the torsional vibrations) and modal coupling problems, and continuous rolling description in multi-stand tandem mill by incorporating the models of tension and delay transfer into the adjacent stands. Furthermore, various nonlinear factors and asymmetrical characteristics are getting more and more attentions and involved in the structural models. The general Slab analysis method for modeling the rolling process is introduced, in which the yield criterions of both homogenous and inhomogeneous deformation, different friction models and stress distribution calculation are presented. Using the Slab analysis method, steady state rolling models, quasi-static rolling models with variation in the gap spacing taken into account, and the dynamic rolling models with both variation and change rate of the gap spacing involved. When the dynamic rolling forces are applied as feedback excitation on the mill structure models, the chatter models can be constructed for investigating the stability and instability criterion.

Key words: chatter, dynamic roll gap spacing, dynamic rolling force, mill structure, rolling process