Additive Manufaturing Trial for Secondary Spacecraft Structures
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The team completed a project for Magellan Aerospace to redesign traditionally manufactured satellite components for fabrication with additive manufacturing (AM) technology. This involved analyzing the feasibility of using AM instead of traditional manufacturing methods. Magellan Aerospace is interested in exploring the benefits of AM technology for component production, assembly, cost, and structural optimization. Compared to traditional manufacturing, AM can rapidly produce highly optimized parts. In this project, an antenna mount bracket was redesigned, and the entire design process was documented for Magellan Aerospace. Autodesk Fusion 360 is a solid modeling software that pairs powerful simulation capabilities with cloud computing to aid in developing an optimized design. The team used Fusion 360’s generative design (GD), a type of simulation that can produce structures from a set of inputs including loads, geometries, and certain design objectives. The team also experimented with running topology optimization (TopOp) studies iteratively to produce a design from a large initial geometry, but design with TopOp was found to be inferior to GD. TopOp was instead used to further optimize GD results. Research into AM technologies found direct metal laser sintering (DMLS) to be the most suitable manufacturing method, given its availability, precision, and ability to produce strong parts. Electron beam melting (EBM) and binder jetting (BJG) were also considered but were rejected due to limitations on compatible materials and dimensional accuracy, respectively. Magellan Aerospace specified that the material used for AM should have similar mechanical and thermal properties to Al-6061 (aluminum), requiring the team to focus on aluminum powders. AlSi10Mg was unsuitable for this project due to heat treatment requirements and difficulty with chemical processing. Specifically, AlSi10Mg requires quenching during heat treatment, which could shatter the geometry of the optimized part. Additionally, the presence of silicon makes chemical processing of these components difficult. A headdCP1 has similar strength and cost to AlSi10Mg, is heat treated via precipitation hardening, and can easily be chemically processed. Therefore, Aheadd CP1 is well-suited for the redesigned bracket. Another post-processing consideration is dimensional accuracy, for which a drawing was created to communicate required tolerances. TopOp studies were run on the GD bracket post-generation to trim remaining unnecessary weight, resulting in a final design roughly 60% lighter than the original bracket. Static load, buckling, and vibration simulations were performed to analyze the bracket’s structural performance. Static and buckling simulations resulted in safety factors of 4.6 and 12.9, respectively. However, results of the vibration study showed that the part had a first mode of frequency of roughly 100 Hz, which did not meet the project specification for vibration performance. Efforts were made to edit the model and increase its natural frequency, but the team was unsuccessful due to software and time limitations. Magellan Aerospace requested a testing plan for verifying component performance. Porosity and the internal structure will be analyzed with CT scans. Structural integrity will be verified with proofload, shock, and vibration testing. Finally, internal and external calipers will be used to verify dimensional tolerances. The final deliverables for Magellan Aerospace are a process for redesigning components for AM, a 3D model of a redesigned antenna bracket, a testing procedure, and a cost analysis for the overall project. The total cost of design, manufacturing, and testing of the bracket is estimated to be $22,132.00 CAD. The team recommends that Magellan Aerospace pursues GD for AM to achieve optimized components according to design specifications.