An Approach for Nesting in Two-Dimensional Stock Cutting Problems

• Main Authors: Shiu, Der-Chin, 許德欽
• Other Authors: 陳漢明
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/99917062091851747558

碩士 === 國立臺灣大學 === 機械工程研究所 === 84 === 　　In the industries for making clothes, shoes, bags, and metal sheets, how to cut more raw materials from stock sheets, i.e., nesting, is essential to the cost of products. In this thesis, a concept of nesting assembly unit is introduced, and a better nesting style is obtained by using that. 　　By taking the irregular shapes into the raw materials with regular size, it must make the waste of the materials. In order to get the nesting assembly unit, the shape features of the sheet stock are first taken into the consideration, therefore, the boundary conditions of the input polygon are reconstructed as the styles of ladder shapes. Secondly, by using the ladder shapes, the procedures of edge-closing are performed by means of pairmatching method. The several polygons are formed into a nesting assembly unit which is the key to solve the nesting problems by taking trimloss rate as a judgment. In the other hand, we enlarge sample space and find the nesting shape which has recursive contour, so that we could obtain the better optimal nesting forms. 　　Finally, the whole process and layout would be displayed by using computer graphics tool, it provides users to select and apply.