Generating optimal T-shape cutting patterns for circular blanks

Circular blanks are often used in the manufacturing of the stators and rotors of electric motors. Some factories in China use T-shape cutting patterns to improve material usage. The author presents an algorithm to generate optimal T-shape cutting patterns for circular blanks. 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 direction 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 principles and steps of the algorithm are described in detail. The computational results indicate that the algorithm is efficient both in computation time and in material usage. Finally, the solution to an example is given.