Applying TRIZ in Design for Additive Manufacturing to Solve Design Contradictions at Multilevel

This article proposes a design framework for additive manufacturing (AM) to solve contradictory design problems. Different structural features are selected within different levels of detail (e.g., cellular structures, infill, porosity) to realize the conflicting requirements and properly combined within the structure of the product. To do this a multilevel interpretation and classification of the options present in a commercial software of Design for AM was provided. Then, criteria to combine the different structural features within the structure of the product were proposed, starting from some principles of the TRIZ (i.e., Russian acronym for “Theory of Inventive Problem Solving”) method. The method was applied to design a dental prosthesis and the results, obtained by testing a simplified plastic sample were analyzed. The contradictory problem deals with the realization of both the mechanical resistance, during the chewing, and the thermal resistance to prevent the thermal dilatation during the workpiece finishing operations on machine tools. The sample designed with the proposed method exhibited better performances in both the requirements compared to another sample, made with a microstructure chosen in a completely random way.