Recursive Algorithm for Generating Two-Staged Cutting Patterns of Punched Strips

The manufacture of parts made of metal sheet often includes two successive processes: the cutting process at which a guillotine shear cuts the sheet into strips, and the punching process at which a stamping press punches out the blanks from the strips. This paper presents an algorithm for generating optimal two-staged cutting patterns of strips for the cutting process. At the first stage the sheet is divided into segments with parallel cuts. Each segment contains strips with the same length and direction. The segments are cut into strips at the second stage. The algorithm calls a recursion function to determine the optimal strip layouts on segments of various lengths, and calls another recursion function to optimally arrange the segments in the sheet, so that the value of the pattern reaches maximum. The computational results indicate that the algorithm is efficient both in computation time and in material usage.