International audienceThanks to the opportunities offered by additive manufacturing (AM) processes, design rules are evolving to lead to lighter and stiffer parts with really more complex shapes than those obtained by conventional processes. Worldwide, new tools of assistance to the design are developed, gathered under the naming “Design for Additive Manufacturing” (DfAM). However, most of the DfAM methods suggested in the literature remain focused on only one component and are not considering the product as a system of components. Moreover, optimizations are mainly limited on reducing the mass or the number of parts, and more rarely on adding some functions.In this article, a new approach is presented to realize a multifunctional optimization of a mechanical system (MS). A methodology is first proposed in order to improve a product by using the AM opportunity. Then, to quantify the improvements of an optimized system, a new design indicator appointed “functional improvement rate” is defined. Finally, a case study, applied to a compressed-air Wobbler engine, is presented to demonstrate the relevance of the methodology and the functional improvement rate. The design adapted to traditional manufacturing is compared to a part-by-part optimized design and a multifunctional optimized design, both adapted to additive manufacturing

In the case of hard machining of steels, negative rake tools generate compressive deformation and high temperature under the cutting edge, leading to phase transformation or ”white layers”. The resulting surface integrity can be predicted by numerical simulations which may be validated by comparing simulated and measured strain fields. Recent high speed imaging devices have facilitated strain field measurement by Digital Image Correlation (DIC), even at high strain rates. However, the analyse is generally restricted to the primary shear zone and not to the workpiece under the machined surface. For this study, a double-frame camera and a pulsed Nd:YAG laser, generally used in the field of fluid mechanics, have been employed to record images during an orthogonal cutting operation of a hardened steel. The effect of the rake angle and the edge preparation of c-BN tools on the subsurface displacement field, which has been experimentally investigated by using DIC, are presented in this paper together with an analysis on the origins of the strains. The results of these measurements will be used to validate cutting numerical simulations or to improve hybrid modelling of surface integrity.WindProcess - ADEM