MODELLING HOT LEVELLING PROCESSES BY UTILISING ARBITRARY LAGRANGIAN EULERIAN (ALE) CONCEPTS

During production of heavy plate, hot levelling is representing an important process step. The ability of simulating the production process including the influence of process parameters on product properties enables to track, guide and control crucial product properties, which is indispensable for modern production lines. The developed system of mathematical modelling components constitutes the basis for overcoming existing shortcomings by a new generation of off-line process models. Eliminating curvature and warping of flat products, caused by preceding production steps is the main purpose of all levelling technologies (e.g. hot and cold levelling and also tension levelling in strip production) and is achieved through repeated alternate bending of heavy plate around multiple levelling rolls, which additionally minimises residual stress. To identify and fully understand the underlying physical effects, Abagus Mwas employed for modelling and analysing the levelling process. Referential data obtained so far from systematic parametric studies form a well founded basis regarding subsequent model reduction techniques. The generalpurpose concept and the primarily Lagrangian formulation of commerical FEM packages in combination with the highly non-linear characteristics of frictional contact, material and geometry may lead to extremely high computational costs. To overcome this problem, customized 2D plane strain models based on the principle of virtual work and a specialised steady-state ALE formalism in conjunction with "Parametric Shape Functions" describing relevant degrees of freedom of the deformed plate are derived, which yield key results like the bending-line and levelling forces.