Manufacturers are constantly encountering tough international competition. In order to stay competitive they have to developed new products with time and cost constraints always more significant. In this context, as a "tool-less‟ and digital approach to manufacture, additive manufacturing presents companies with a wide and expanding range of technical and economic benefits. However, the additive manufacturing processes, as the others, have also their own characteristics and limits. Finally, to take advantages of the technological breakthrough which is additive manufacturing, a new way of designing products is needed. This work deals with the development of a new methodology of design for additive manufacturing. Subdivided in four main steps, the proposed method allows from functional specifications and manufacturing process characteristics to define an optimized part geometry regarding both the functional objectives and the manufacturing constraints. In the first step, manufacturing orientations are chosen from the functional entities and allow to propose a design area. The general topology of the part is then optimized in this area regarding the functional specifications and the global manufacturing constraints. In the third step, the accurate part geometry is generated from a choice of manufacturing trajectories and thanks to the manufacturing process simulation. The fourth and last step are to determine and compare each other the different geometries corresponding to all the possible choices of manufacturing strategy. At the end, the best suitable is selected. The proposed method structure is generic and can be applied to all the additive manufacturing processes. However, the physical phenomena involved during the manufacturing processes are different for each one; the manufacturing constraints can be thus also different. This work deals more specifically with the laser cladding technology. Indeed, a physical model of this process has been proposed. It allows estimating and optimizing the manufacturing strategies regarding the functional needs and the manufacturing constraints. This model has been particularly used in the optimization method of manufacturing paths which has also been developed in this work to manufacture thin wall metal parts.
