A two-dimensional bin packing problem with size changeable items for the production of wind turbine flanges in the open die forging industry

Abstract

Efficient cutting design is essential to reduce the costs of production in the open die forging industry. This article discusses a slab cutting design problem that occurs when parallel piped items are cut from raw material steel slabs with varying widths and lengths to meet a volume requirement. The problem is modeled as a two-dimensional cutting stock problem or bin packing problem with size-changeable items. Cut loss and guillotine cut constraints are included. A knapsack-based heuristic algorithm is proposed and it is tested by a real-world manufacturer who is cutting steel for wind turbine flanges. The firm generates an annual cost reduction of approximately US $2000 000.