Two-dimensional placement optimization for multi-parts production in additive manufacturing

Additive Manufacturing (AM) processes build parts in a layer by layer manner. This unique characteristic enables AM machines to fabricate different parts simultaneously without using tools or fixtures. However, how to optimally place multi-parts (with same or different geometries) into a specified build space or onto the build platform with respect to user-defined objectives is a complex NP-hard problem. This problem is a special variant of classical nesting or packing problems. Moreover it owns specific constraints from AM. In this paper, the multi-parts placement problem in AM is analyzed and an integrated strategy is proposed to solve one category of the problem, two-dimensional placement of multi-parts. The proposed strategy is composed of two main steps, Applying an "AM feature-based orientation optimization method" to optimize each part's build orientation to guarantee the production quality and Applying a designed "parallel nesting" algorithm for increasing the compactness of placement by using the parts' projection profiles so as to decrease the total build time and cost. Computational examples are presented in the end for demonstration.