Date of Award
Summer 8-12-2022
Level of Access Assigned by Author
Open-Access Thesis
Degree Name
Master of Science in Mechanical Engineering (MSME)
Department
Mechanical Engineering
Advisor
Bashir Khoda
Second Committee Member
Masoud Rais-Rohani
Third Committee Member
Keith Berube
Abstract
Lattice structure manufacturing with polymers and metals can benefit from the use of Eulerian paths. In this research, two types of lattice fabrication methods are studied where the Eulerian path can be applicable. Polymer lattice is improved by using a new assembly design, while a new way of metal lattice fabrication is discussed.
For the fused filament fabrication process, a new interlocking design and assemble-based lattice structure building approach is investigated by increasing continuity in layers and avoiding support structures. To minimize contour plurality, Eulerian paths between the edges were enforced. Two configurations in the form of cubic and octet lattice structures are examined. The compressive performance of the designed lattice structures is compared with the traditional single-build direct 3D printed lattice structures. The mechanical performance (e.g., peak stress, specific energy absorption) of the assembled structures is found to be generally better than their direct print counterparts. The empirical constants of the Ashby-Gibson power law are found to be larger than their suggested values in both direct print and assembly techniques. However, their values are more compliant for octet assembled structures, which are less susceptible to manufacturing imperfections.
A novel method of metal lattice manufacturing is introduced where a straight wire is bent to make intermediate structures, they are stacked, and loose nodes are joined to get the final lattice. The limitations of this method are studied, and a machine is constructed that can overcome some of the limitations and produce fabricable and stackable structures. These structures, generated by a custom-made visual basic code, can be periodic or aperiodic using a function to optimize the topology. The transient liquid phase (TLP) diffusion bonding method is studied as an appropriate joining method due to the inaccessibility of the nodes after stacking.
Recommended Citation
Alam, Adeeb Ibne, "Additively Manufactured Polymer and Metal Lattice Structures with Eulerian Path" (2022). Electronic Theses and Dissertations. 3636.
https://digitalcommons.library.umaine.edu/etd/3636