A Multi-Level Approach for the Mechanical Design of Cluster Mills for Cold Rolling of Thin Steel Products

So-called “cluster mills” for cold rolling are currently preferred to prevent strip faults, as the back-up rolls present on the work rolls assure the stiffness required to avoid bending. An effective prediction of dynamic behaviour using an analytical approach is more difficult than for 2 and 4-high mills. The aim of this paper is to find models to simulate operating conditions in cluster mills. Two typical test cases such as Sendzimir and Z-mill are used to detect relevant aspects of dynamics on the experimental signatures, acquired in service. A multi-level approach, based on a core mill model and on some additional models, is proposed to investigate second order approximation problems. Co-simulation with the core model is avoided, as it takes too long. Phenomena, models, available tools and implementation issues are systematically analysed, while a preliminary experimental validation of results, based on available industrial mills, is discussed.