Additive Manufacturing of a Reverse Engineered and Generatively Designed Legacy Part

Abstract Additive manufacturing (AM) and generative design tools are gaining popularity in reverse engineering and design optimization. Many industries, including aerospace and automotive, seek to reduce the mass of critical components while maintaining desired strength. The benefits of more efficient structural components include manufacturing cost savings across industries, increased fuel economy in transportation, and greater payload capacity in aerospace applications. This study utilized techniques such as 3D scanning, Fusion-based generative design simulations, and 3D printing to create a more efficient and equally strong component using advanced computer and manufacturing technologies. This study focused on an engine mount bracket for a Honda comfortable runabout vehicle (CRV), part number 11910-PPA-000, selected for generative design simulations and 3D printing as its dimensions were optimal for a commercially available desktop 3D printer and defined features ideal for 3D scanning and material testing. Once scanned, the stereolithography (STL) file was processed using Autodesk ReCap Photo to convert the triangular STL facets to quadrilateral facets before conversion to a meshed object in Fusion for further processing in the Design and Generative Design workspaces. The bolt and tapped holes were then isolated from the body of the mount bracket using the Fusion body splitting tool before post-processing to remove scanning defects from the inside face of the fixture points. The mounting bracket was then processed in the Fusion Generative Design workspace using acrylonitrile-butadiene-styrene (ABS) as the assigned material. The entire part was designated as the starting shape, with each bolt hole designated as preserved geometry, and established obstacle geometry to set the boundaries for the generative design. After assigning the part geometry, structural constraints and loads were applied to be consistent with the expected fixture points during testing, and the manufacturing type was designated for additive manufacturing. A model was then selected from 10 different generative design studies based on the mass saved and maximum Von Mises stresses. The chosen outcome had a mass reduction of 34%, from an original 131 grams to 86 grams when designed from ABS plastic. The maximum von Mises stress for the generative design was shown to be 9.8 MPa with a minimum factor of safety of 2. Three parts were printed out of ABS using 0°, 90°, and 45°/−45° raster orientations from the generative design. In addition, the legacy mount bracket was printed out of ABS using a 45°/−45° raster orientation from the generative design. The legacy part was tested on an Instron universal testing system as a benchmark for future testing of the generative design parts. The comparative study of a 3D scanned legacy part with generative design models demonstrated the feasibility of reverse engineering parts. This study also enabled advanced simulation tools to reduce the processing chain compared to traditional manufacturing and increase efficiency for critical parts across multiple industries.