A three-dimensional thermo-mechanical finite element model of complex strip rolling considering sticking and slipping friction

Friction plays an important role in the theory and practice of rolling. Previous research has shown that the friction coefficient varies in the roll bite when hot rolling steel can include sticking and slipping regimes. In order to improve the accuracy of modelling, in this paper, the authors present a three-dimensional thermo-mechanical simulation of the complex strip rolling, considering friction variation model with sticking friction and slipping friction by a three-dimensional rigid–visco-plastic finite element method. The theoretical analysis is based on the utilisation of the finite element flow formulation to characterise the material flow, to predict the metal flow and temperature, and to estimate roll separating force and rib height. The length of the sticking zone is determined dynamically and the friction variation was considered for both the top and bottom surface of the strip. The numerical predictions were verified by the experiments performed in a hot strip mill. Results of the simulation show that when the friction variation is considered and the thermal and mechanical combination is conducted, the computed values are in good agreement with the experimental values.