COMPUTER AIDED NESTING OF DISSIMILAR PARTS WITH BOUNDARY CONSTRAINTS

Abstract

A computer generated solution to an optimized layout for irregular 2-dimensional shapes has been developed. The aim is to provide a general solution that can be applied to many industries such as flame cutting in shipbuilding, leather cutting, garment manufacturing and furniture construction, among others. Common constraints pertaining to the layout of 2-dimensional shapes e.g. irregular boundaries, are considered but technical requirements in any one industry such as cutter compensation and heat distortion effects in flame cutting applications are too specific and would have to be addressed when customizing the solution to a particular application. Constraints that are addressed in this research include boundary conditions - whether irregular, regular or unbounded: bad patches within the sheet which makes certain portions unusable; and bridge width which is the minimum separation between adjacent shapes. The computer program generates an automatic layout in a computation time which is typically less than 20 minutes on a HP9836 computer. The actual time required depends largely on the complexity and number of shapes involved. An interactive routine is also provided to allow the user to make adjustments to the automated layout, if desired.