Some principles to optimise an additively manufactured multi-component product

Depending on the requirements, the design of a product may result in very different solutions. Topological optimisation is a mathematical tool that can be used to obtain lighter parts without decreasing their stiffness. As the optimised part shapes are often too complex to be manufacturable, additive manufacturing is generally used. Usually, the topological optimisation is performed on a single part. However, for a product, the decreasing of mass and inertia in each individual part has an impact on the loads applied onto all the parts of the system. Moreover, different paths can be used to optimise a product, e.g. optimising all the parts simultaneously or part after part. Therefore, the aim of this paper is to propose, based on a case study, some optimisation principles to find the best optimisation path to design an additively manufactured product. In order to do this, the concept of topological optimisation loops is first proposed. Then, several optimisation paths are compared. In comparison with a usual single topological optimisation, the proposed method leads to an additional gain in mass of up to 35% for the case study. Finally, some optimisation principles are suggested to choose the most adapted path according to the designer objectives.