الفهرس 
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Abstract
This work reports on the design of a computer-aided sheet nesting system (CASNA) for the nesting of two different or two similar shaped sheet-metal blanks on a given sheet stock or coil stock. The objective is to maximize material utilization and thus reduce material wastage. The problem emerges in various form in a number of industries such as ship-building, sheet metal, aerospace, glass, clothes and footwear. In some of these industries, small savings in material costs can considerably affect the profitability of the operation. Therefore, considerable care and expertise is devoted to obtaining a reasonable layout with good material utilization. The system extracts the required shape geometrical information directly from the program data base. Initially, the two shapes are overlapped and the different positions can be obtained by fixing the first shape and moving the second in steps in X-direction until no overlapping occurs. After that, the movable shape is moved by steps in Y-direction and repeated the motion in X-direction. Trials after, rotating the movable shape with mirroring the shape in horizontal and vertical direction taking grain orientation constrains into a consideration. In each case the system determines the material utilization by calculating the minimum circumscribing rectangular area which contains the two shapes. The developed system has been written in ” Visual-C” on an IBN-Compatible personal computer. The optimum nesting is calculated from overall trails. The system is applied on different shapes and proved to give a reduced computation time for arriving to the optimal position with higher utilization ratio and minimization of scrap.
Work piece shapes may vary from being simply rectangular to being highly intricate. The optimal solution for rectangular work pieces is simpler because it involves fewer options to work piece orientation. This is due to the fact that in most cases, stocks are rectangular in shape and, therefore, an optimal solution will be based on one where all the rectangular work piece shapes are aligned parallel to the stock edges. On the other hand, irregular complex shapes require testing a large number of orientations and shape arrangements.