3D analysis of cold rolling using a constitutive model for interface friction

Full three-dimensional numerical analyses are carried out for the cold rolling of plates of finite width, to study the effect of the width spread during rolling. The contact and friction between roll and plate is modeled in terms of an interface constitutive model that accounts for the friction forces in the rolling direction as well as those in the transverse direction that give resistance to the width spread. At low normal pressures Coulomb friction is represented while at high normal pressure a yield stress limitation of the maximum tangential stress is incorporated, and slip as well as no slip is accounted for. Finite strain elasto-plasticity is applied for the plate material, using mostly isotropic hardening or in a few cases kinematic hardening to represent the effect of a rounded vertex on the yield surface. In addition, for a given plate thickness and degree of reduction the effect of different values of the roll radius and the effect of different values of the plate width are analysed.