CNR ExploRA

Articolo in rivista, 2020, ENG, 10.1007/s11837-019-03886-x

Parametric shape optimization for combined additive-subtractive manufacturing

L. Tamellini, M.Chiumenti, C. Altenhofen, M. Attene, O. Barrowclough, M. Livesu, F. Marini, M. Martinelli, and V. Skytt V.

Consiglio Nazionale Delle Ricerche, Istituto di Matematica Applicata e Tecnologie Informatiche (CNR-IMATI), Pavia, Italy; International Center for Numerical Methods in Engineering (CIMNE), Universidad Politécnica de Cataluña, Barcelona, Spain; Fraunhofer Institute for Computer Graphics Research IGD, Interactive Engineering Technologies, Darmstadt, Germany; Interactive Graphics Systems Group, Technische Universität Darmstadt, Germany; Consiglio Nazionale Delle Ricerche, Istituto di Matematica Applicata e Tecnologie Informatiche (CNR-IMATI), Genova, Italy; SINTEF Digital, Mathematics and Cybernetics, Oslo, Norway

In industrial practice, additive manufacturing (AM) processes are often followed by post-processing operations such as heat treatment, subtractive machining, milling, etc., to achieve the desired surface quality and dimensional accuracy. Hence, a given part must be 3D-printed with extra material to enable this finishing phase. This combined additive/subtractive technique can be optimized to reduce manufacturing costs by saving printing time and reducing material and energy usage. In this work, a numerical methodology based on parametric shape optimization is proposed for optimizing the thickness of the extra material, allowing for minimal machining operations while ensuring the finishing requirements. Moreover, the proposed approach is complemented by a novel algorithm for generating inner structures to reduce the part distortion and its weight. The computational effort induced by classical constrained optimization methods is alleviated by replacing both the objective and constraint functions by their sparse grid surrogates. Numerical results showcase the effectiveness of the proposed approach.

JOM (1989) 72 , pp. 448–457