Modification of a classical formula for determination of roll flattening in flat rolling

Abstract

Local elastic roll flattening in direction of the roll axis in flat rolling is one of the important displacement components related to the roll gap shape. Up to now some classical formulae to solve roll flattening have been proposed. These formulae were derived from the elastic half space theory or the 2-dimensional contact theory. On calculating the flattening of the back-up roll they may result in a great deviation. In the present effort a comparison was made between the flattening results obtained by a 3-dimensional finite element method and by a classical formula. The relation between the deviation and the back-up roll geometry was also examined and therefore the classical formula was modified. Calculated results indicate that the modified formula can more accurately predict the back-up roll flattening.Modlflzlerung einer klassischen Formel fOr die Bestimmung der Walzenabplattung beim Flachwalzen. Die i:irtliche elastische Walzenabplattung Ober der Ballenbreite beim Flachwalzen ist eine wichtige Verformungsgri:iBe far die Bestimmung der Walzspaltform. Bisher wurden einige klassische Formeln fur die Li:isung der Abplattung benutzt, die von der Theorie des elastischen Halbraums bzw. von der Theorie des ebenen Kontakts abgeleitet wurden. Solche Formeln liefern jedoch groBe Abweichungen bei der Berechnung der Abplattung der StOtzwalze. Beim Vergleich der Abplattungen, die mit der drei-dimensionalen Finite-Elemente-Methode und mil einem klasslschen Modell ermittell wurden, konnte eine Beziehung zwischen den Abweichungen und der Walzengeomelrie fsststellt werden. Damit wurde die Formel angeglichen. Die Berechnungen zeigen, daB die Abplattungen der StOtzwalzen mit der modifizierten Formel genauer bestimmt werden ki:innen. formula [7] so that it can calculate the back-up roll flattening as accurately as possible.

Contact mechanics and work roll wear in cold rolling of thin strip

“…Hacquin et al [10] developed a refinement of the roll bending and flattening models for strip rolling. Zhou et al [11] gave better precision thanks to the introduction of corrective terms, based on elasticity theory, but also on comparison with a FEM single roll deformation model. Matous and Maniatty [12] used a new and updated Lagrangian formulation to model the elasto-viscoplastic behaviour in polycrystalline materials.…”

Modification of Roll Flattening Analytical Model Based on the Plane Assumption

“…Then, the mechanics of the cold strip rolling was analyzed based on the model. Zhou et al [21,22] [23][24][25][26][27] analyzed the error of semi-infinite body model in roll calculation and proposed an analytical model in flat rolling by boundary integral equation method. Wang et al [28] used the 3-D elastic-plastic FEM to simulate the thin strip rolling process of UCM cold rolling mill.…”

Modeling of Strip Shape during Cold Rolling of Thin Strip

“…Hacquin et al [14] developed a refinement of the roll bending and flattening models for strip rolling. Zhou et al [15] introduced corrective terms, based on elasticity theory, but also on comparison with a FEM single roll deformation model. Matous & Maniatty [16] used a new and updated Lagrangian formulation to model the elasto-viscoplastic behaviour in polycrystalline materials.…”