Generating optimal T-shape cutting patterns for rectangular blanks

Both the material usage and the complexity of the cutting process should be considered in generating cutting patterns. This paper presents an algorithm for generating guillotinecutting patterns for rectangular blanks. It simplifies the cutting process by allowing only one size of blanks to appear in a strip. The direction of a strip is either in the sheet length direction or in the sheet width direction. The algorithm uses an implicit enumeration method and the knapsack algorithm to determine the optimal combination of strips and strip directions to make the material usage reach its maximum. The algorithm is compared with the well-known two-stage algorithm through experimental computations. The computational results indicate that the algorithm is efficient both in computation time and in material usage, and it is able to simplify the cutting process greatly. Finally, the solution to an example is given.