2021/08/05 by Amir M. Mirzendehdel, Mirzendehdel, Amir M., Morad Behandish +3 · 2 citations
Engineering · #Topology Optimization in Engineering #Manufacturing Process and Optimization
paper · pdf · doi:10.48550/arxiv.2108.02829
Metal additive manufacturing (AM) processes often fabricate a near-net shape\nthat includes the as-designed part as well as the sacrificial support\nstructures that need to be machined away by subtractive manufacturing (SM), for\ninstance multi-axis machining. Thus, although AM is capable of generating\nhighly complex parts, the limitations of SM due to possible collision between\nthe milling tool and the workpiece can render an optimized part\nnon-manufacturable. We present a systematic approach to topology optimization\n(TO) of parts for AM followed by SM to ensure removability of support\nstructures, while optimizing the part's performance. A central idea is to\nexpress the producibility of the part from the near-net shape in terms of\naccessibility of every support structure point using a given set of cutting\ntool assemblies and fixturing orientations. Our approach does not impose any\nartificial constraints on geometric complexity of the part, support structures,\nmachining tools, and fixturing devices. We extend the notion of inaccessibility\nmeasure field (IMF) to support structures to identify the inaccessible points\nand capture their contributions to non-manufacturability by a continuous\nspatial field. IMF is then augmented to the sensitivity field to guide the TO\ntowards a manufacturable design. The approach enables efficient and effective\ndesign space exploration by finding nontrivial complex designs whose near-net\nshape can be 3D printed and post-processed for support removal by machining\nwith a custom set of tools and fixtures. We demonstrate the efficacy of our\napproach on nontrivial examples in 2D and 3D.\n