Application of 2-dimensional FEM to predict the thickness profile in 4-high mills

In order to investigate the strip crown and edge drop effects in cold and h ot mills with special crown rolls (SCR) under a specific roll force a a-dim ensional finite element model was developed. Using a technique of inversion of condensed stiffness matrix formed by eliminating ail the nodes except t hose where contact is likely to take place, the contact pressure between wo rk mil and backup roll can be effectively obtained. This model is somewhat faster than a 3d FE model, but slower than the slit model derived from the simple beam theory. However, the 2d FE model can deal with any roll geometr y and include the profile control means of roll bending and shift. Besides, with this model, it is easy to consider the influence of strip divergence, transverse friction force and work roll contact on the strip profile/crown . Numerical simulations have shown the effect.