Research on optimal layout techniques of NC metal cutting for polygonal metal part

In the NC metal cutting process, the cutting parts must be nested on a metal sheet carefully in order to minimize material waste. Compared to the parts layout in die stamping process, there are more cutting parts in NC metal cutting, their types and shapes usually are also more complicated. All above will give out large difficulties to computer aided parts layout, especially to arbitrary polygonal metal parts. Aimed at above problems, a two-phase method is presented in this paper. Firstly, the whole cutting parts are classified into two sets—the layout parts set and filling parts set by their shapes and areas. Secondly, layout optimization of arbitrary polygonal parts in the layout parts set is performed by genetic algorithm (GA). In order to improve the convergent stability and speed, niche technology and adaptive operator are used in GA. Finally, a grid dividing and filling algorithms are studied which is used to insert other parts in the filling set into the interspace between the nested parts. Above algorithms are carried out by VC++, and the results show that the material utilization is improved obviously.