Concept of Optimal Bar Roll Pass Design. Report 4. Optimization of Roll Pass Design Scheme

Abstract

Abstract: This study considers roll pass design from the standpoint of system-level analysis within the UrFU concept of optimal roll pass design developed at the Department of Metal Forming of the Ural Federal University. Roll pass design as a process system is changed by two methods, that is, either by changing the structure of the system, which corresponds to changes in the groove shape, or by changing the control of the system, which corresponds to changing reductions by passes in one and the same grooves, that is, by changing reduction mode. The roll pass design that is considered optimal contains such grooves and uses such reduction mode, at which the extreme properties of preset target functions are ensured depending on the indicated parameters. In previous reports, the general concept of the two-stage optimization of roll pass design is considered. This concept implies a consistent optimization of the roll pass design scheme (optimization stage one) and reduction mode (optimization stage two). In addition, procedures of shaping the optimization space for stage one are considered. This space includes virtual roll pass design schemes and is shaped by the special generator of these schemes and the set of all possible types of grooves that can be used at this particular stage of rolling. To calculate the target function of the optimality criterion of the roll pass design scheme, the groove efficiency space concept is introduced. This space is shaped by the formalized expert assessment of the degree of influence of various permissible forms of grooves used in roll pass design on the diverse technological, economic and other characteristics of a particular rolling mill. The target function is calculated as variance of integral performance indicators of the grooves included in the roll pass design relative to the hypothetical ideal groove with the best values of selected performance indicators. The roll pass design scheme corresponding to the minimal target function is considered the best. © 2022, Allerton Press, Inc.