Lorenz Steinwender, Alexander Kainz, Konrad Krimpelstätter, Klaus Zeman,
"An Arbitrary Lagrangian-Eulerian (ALE) Approach for the Modelling of Tension Levelling Processes"
, in E.Onate, D.R.J.Owen, D.Peric, B.Suarez: Computational Plasticity XI - Fundamentals and Applications (COMPLAS XI), International Center for Numerical Methods in Engineering (CIMNE), Gran Capitan, 08034 Barcelona, Spain, 9-2011, ISBN: 978-84-89925-23-6
An Arbitrary Lagrangian-Eulerian (ALE) Approach for the Modelling of Tension Levelling Processes
Sprache des Titels:
Computational Plasticity XI - Fundamentals and Applications (COMPLAS XI)
Strip flatness and surface quality are crucial factors for the production of high-quality cold-rolled metal strips. Tension levelling (employed as one of the final steps in continuous galvanizing and finishing lines) improves strip flatness and minimizes residual stresses by inducing small elasto-plastic strip deformations, while the strip is bent under high tension stresses around multiple rolls with small diameters.FEM-simulations of tension levelling processes are particularly challenging as the small and coupled elasto-plastic deformations occur simultaneously at concentrated regions along the strip bending line. Steady-state solutions cannot be reached before at least one strip cross-section has passed through the entire process unit of the tension leveller. These requirements lead to simulation models with a large number of degrees of freedom, and ? in combination with the highly non-linear characteristics of contact, material and geometry ? to excessive computational efforts even on modern mainframes.
To overcome the high computational costs of FEM simulation models, a new and alternative modelling approach, based on the principle of virtual work and a specialised ?Arbitrary Lagrangian-Eulerian? (ALE) formalism has been elaborated. This novel concept is based on ?Parametric Shape Functions? (PSF) that describe both geometry and strain distribution of the deformed strip. The decoupled movement of material and mesh in the ALE description allows for the implementation of highly efficient contact algorithms while the strip length under consideration can be minimised. Hence, compared to commercial FEM-models, the PSF-model exhibits a drastic reduction of degrees of freedom and computational costs (by a factor of 100 and more in typical test cases) and simultaneously maintains high agreement of the key results.
Sprache der Kurzfassung:
International Center for Numerical Methods in Engineering (CIMNE)