Determining the optimum cut of sheet roll material

Abstract

The profitability of forging and stamping plants is directly related to the economical use of raw materials. For sheet metal stamping, material losses can account for a significant proportion (up to 20-40%), so reducing them even by a few percent saves thousands of tonnes of sheet metal. An indicator of material utilisation efficiency and rationality of cutting is a material utilisation factor η, defined as a ratio of the weight of the workpiece to the rate of material consumption for its production. The value of material efficiency depends largely on the shape of the manufactured part, its location on the sheet (strip), and the size of the sheet (strip). One of the ways to save sheet material is by transferring parts from individual sheets to stamping directly from the sheet roll. Calculations for some types of products showed that the transition from pre-cutting of metallurgical rolling on guillotine or disk shears to cutting directly from the roll gives more than 3% of savings, and with chess-cutting this economy increases by 3-5 times. Bearing this in mind, it is of interest to find the optimum, in terms of economy of material, cutting of sheet coils when cutting out parts of various shapes, including round ones. This study solves the problem of determining a rational variant of sheet coil cutting for different sizes of sheet coils supplied by factories and diameters of cut out circles.