Stamping strip layout for optimal raw material utilization

Nye, T. J.

doi:10.1016/s0278-6125(01)80003-0

Cited by 17 publications

(20 citation statements)

References 18 publications

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“…8 The shape used in comparison of results with a Ref. [5] and b the resulting NFPh animations. It is a platform for two-dimensional graphics made of two parts: an XML-based file format and a programming API for graphical applications.…”

Section: The No Fit Polygon and The No Fit Pathmentioning

confidence: 99%

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Optimal positioning of irregular shapes in stamping die strip

Licari

Valvo

2010

Int J Adv Manuf Technol

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The nesting of two-dimensional shapes is a common problem, where raw material has to be economically cut. As for the single-pass single-row strip layout, several algorithms, based on established methods, have been proposed. Moreover, it should be noticed that the optimum layout should also consider a few constraints, like grain orientation for subsequent forming operation, correct bridge width, and the commercial roll of metal width in order to make solutions applicable in real industrial environments. Most of the procedures until now shown in literature are quite complex and often ignore these real constraints. They usually make use of sliding techniques and are not able to effectively work with relatively multiple-connected figures. In particular, most of the different proposed procedures are based on the No Fit Polygon (NFP) computation of non-convex polygons, which often generates holes. This work is a proposal for a more efficient method, which can be used in heuristic procedures. In order to overcome some faults of most of the former methods presented in literature, in this paper a new geometric entity called "No Fit Path" (NFPh) of nonconvex polygons is applied. It allows researchers to find solutions of nesting problems even when there are NFP faults due to degenerate solutions. Moreover, the No Fit Path allows researchers to easily read, modify, or share their results, overcoming all those problems arising from the usual large amount of information and from the different origins and formats of the obtained data. Given two nonconvex polygons, the algorithm is able to calculate their NFPh very quickly and without any approximation by a polygon clipping method. In this paper a totally automated procedure has been developed. This procedure firstly obtains the "No Fit Path" (NFPh); secondly, between all the existing positions on the NFPh, the algorithm searches the optimal one, minimizing the global waste. The proposed approach also allows designers to set an optimal orientation of the shapes on the roll of metal, taking account of the grain orientation in order to obtain the best mechanical characteristics for the cut pieces.

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Section: The No Fit Polygon and The No Fit Pathmentioning

confidence: 99%

“…In the past some authors have faced this problem by using a tool called No Fit Polygon (NFP) [3][4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Optimal positioning of irregular shapes in stamping die strip

Licari

Valvo

2010

Int J Adv Manuf Technol

View full text Add to dashboard Cite

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“…Finally the expert system is tested for brass sheet metal for its validity. An interesting work was conducted (Nye, 2000) which is aimed to design strip layout for optimal raw material utilization based on the 'Minkowski sum'. According to this concept, if two blanks are considered, 'A' and 'B', they will overlap only if A (-B) contains the origin.…”

Section: Illustrations (If Any)mentioning

confidence: 99%

“…This property leads to the mapping of 'strip pitch' -distance to the edge of the Minkowski sum, and 'strip width' -maximum perpendicular distance between the strip longitudinal axis (through the origin) and the perimeter of A (-B). The material utilization can be easily calculated as a function of blank orientation, once the Minkowski sum is generated (Nye, 2000). The strip orientation in the parent sheet is represented by 'sweepline' vector, which sweeps through a range of orientations and is anchored at the origin.…”

Section: Illustrations (If Any)mentioning

confidence: 99%

“…The raw material utilization, strip width and pitch were evaluated with the help of expressions derived. This concept of strip layout design is demonstrated by T-shaped blank, for which the optimal blank orientation occurs at θ = 18.43° and 161.56°, with a corresponding material utilization of 53.3% (Nye, 2000). The metal stamping layouts using analytic hierarchy process method is also an important contribution for strip nesting design (Rao, 2004).…”

Section: Illustrations (If Any)mentioning

confidence: 99%

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