Exact algorithm for generating two-segment cutting patterns of punched strips

Metal plates are often divided into items in two stages. First a guillotine shear cuts the plate into strips at the shearing stage, and then a stamping press punches out the items from the strips at the punching stage. This paper presents an algorithm for generating optimal two-segment cutting patterns of strips at the shearing stage. An orthogonal cut divides the plate into two segments, each of which contains strips of the same direction and length. The algorithm uses dynamic programming techniques to determine the optimal strip layouts on segments of various lengths, and selects two segments to appear in the optimal pattern. The segments are considered in increasing order of their lengths, so that dominant properties can be used to shorten the computation time. The computational results indicate that the algorithm is efficient in both material utilization and computation time.