Additive manufacturing-enabled design theory and methodology: a critical review

As additive manufacturing (AM) process evolves from rapid prototyping to the end-of-use product manufacturing process, manufacturing constraints have largely been alleviated and design freedom has been significantly broadened, including shape complexity, material complexity, hierarchical complexity, and functional complexity. Inevitably, conventional Design Theory and Methodology (DTM) especially life-cycle objectives oriented ones are challenged. In this paper, firstly, the impact of AM on conventional DTM is analyzed in terms of design for manufacturing (DFM), design for assembly (DFA), and design for performance (DFP). Abundance of evidences indicate that conventional DTM is not qualified to embrace these new opportunities and consequently underline the need for a set of design principles for AM to achieve a better design. Secondly, design methods related with AM are reviewed and classified into three main groups, including design guidelines, modified DTM for AM, and design for additive manufacturing (DFAM). The principles and representative design methods in each category are studied comprehensively with respect to benefits and drawbacks. A new design method partially overcoming these drawbacks by integrating function integration and structure optimization to realize less part count and better performance is discussed. Design tools as a necessary part for supporting design are also studied. In the meantime, the review also identified the possible areas for future research.