A cutting stock problem and its solution in the manufacturing industry of large electric generators

T-shape cutting patterns are applied in the manufacturing of circular and sectorial blanks for stators and rotors of large electric generators. The author presents an algorithm to generate them. In the patterns more than one row of identical blanks can appear in a strip. A strip is in one of the two perpendicular directions, namely X- or Y-direction. The algorithm uses the knapsack algorithm and an implicit enumeration method to determine the optimal combination of blank rows in the strips, the strip numbers and directions in the pattern. The algorithm is applied to the real cutting stock data of a factory that makes large electric generators. The results indicate that the algorithm is efficient both in computation time and in material usage.