A Novel Approach for the Modeling of Tension Leveling Processes by Employing Parametric Shape Functions
Sprache des Titels:
METEC InSteelCon 2011 Proceedings
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 the strip flatness and minimizes residual stresses by inducing small elasto-plastic strip deformations, while the strip is bent under high tension around multiple rolls with small diameters.
To improve the design process for such tension levelling machines, precise models are essential, yielding key results like the bending line, the reaction forces at the bending rolls, the required level of tension, the tension losses (due to plastic deformation) as well as the power requirements of the drives.
Extensive analyses of the tension levelling process employing commercial FEM-packages led to a comprehensive understanding of the underlying physical effects and correlations. However, up to several million degrees of freedom are required for significant and reliable 3D FEM-simulations, which leads to unacceptable calculation run times even on modern mainframes.
In order to reduce the extensive computational costs of 3D FEM-models (while assuring a high significance of results), a new and highly specialised modelling approach based on the principle of virtual work and parametric shape functions for the curvature and the strain distributions was developed. Compared to optimised FEM-models, this tailor-made model allows a drastic reduction of degrees of freedom and computational costs, while the key simulation results are equivalent.
Due to their efficiency and reliability, the developed methods yield the potential to be used in large-scale parametric studies in the design phase of tension levellers ? leading to an optimised process and equipment, improved plant performance and significant reduction of energy costs.