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 sh...

This work presents a hybrid optimization framework for tackling cutting and packing problems, which is based upon a particular combination scheme between heuristic and exact methods. A metaheuristic engine works as a generator of reduced instances for the original optimization problem, which are formulated as mathematical programming models. These instances, in turn, are solved by an exact opti...

We consider the problem of guillotine cutting a rectangular sheet into rectangular pieces with two heights. A polynomial time algorithm for this problem is constructed.

Two-dimensional bin packing problems are highly relevant combinatorial optimization problems. They find a large number of applications, for example, in the context of transportation or warehousing, and for the cutting of different materials such as glass, wood or metal. In this work we deal with the oriented two-dimensional bin packing problem under free guillotine cutting. In this specific pro...

This paper deals with the classical two-dimensional cutting stock problem, which consists of generating cutting patterns to produce bi rectangular items of sizes (li,wi), i=1,..,m, from rectangular objects of sizes (L,W), so that an objective is optimized, for example, the cost or trim loss. However, to cut the patterns they should be sequenced in such a way as to optimize another objective, fo...

We consider a Two-Dimensional Cutting Stock Problem (2DCSP) where stock of different sizes is available, and a set of rectangular items has to be obtained through two-stage guillotine cuts. We propose and computationally compare three Mixed-Integer Programming models for the 2DCSP developing formulations from the literature. The first two models have a polynomial and pseudo-polynomial number of...

In this work a solution using evolutionary algorithms with penalty function for the non-guillotine cutting problem is presented. In this particular problem, the rectangular pieces have to be cut from an unique large object, being the goal to maximize the total value of cut pieces. Some chromosomes can hold pieces to be cut, but some pieces cannot be arranged into the object, generating infeasib...

PVC frame cutting process by guillotine is a common method that attracted attention of car parts and PVC decorating furniture producers. In this paper, the effects of main parameters such as cutting speed, lubricants and cutting frame holder pressure force on PVC frame section surface smoothness is investigated by experimental methods on a specified PVC frame sample and then by FEM simulation u...