Scalable, process-oriented beam lattices: Generation, characterization, and compensation for open cellular structures

Date
2021-12-01
Journal Title
Journal ISSN
Volume Title
Publisher
Additive Manufacturing
Abstract
Additively manufactured lattices are emerging as promising candidates for structural, thermal, chemical, and biological applications. However, achieving a satisfactory prototype or final part with this level of complexity requires synthesis of disparate knowledge from the distinctly digital and physical processing stages. This work proposes an integrated framework for processing self-supporting, open lattice structures that do not require supports and facilitate material removal in post-processing steps. We describe a minimal yet comprehensive design strategy for generating uniform lattice structures with conformal open lattice skins for an arbitrary unit cell configuration. Using continuous liquid interface production (CLIP™) on a Carbon M1, printability is evaluated for five unique bending-dominated lattice structures at unit cell length scales from 0.5 to 3.5 mm and strut diameters ranging from 0.11 to 1.05 mm. Using a cubic lattice as a basis, we further examine dimensional fidelity with respect to 2D lattice void dimensions and part position, finding differences between length scales and within parts, due to physical processing artifacts. Finally, we demonstrate a functional grading strategy based on process control methods to compensate for dimensional deviations. Using an iterative approach based on a naïve process model, deviation of the planar strut radius in a cubic lattice was decreased by approximately 85% after two iterations. These insights and strategies can be readily applied to other structures, characterization techniques, and additive manufacturing processes, thereby improving the exchange of information between digital and physical processing and lowering the energy barriers to producing high-quality lattice parts.
Description
© 2021 The Author(s). This article was originally published in Additive Manufacturing. The version of record is available at: https://doi.org/10.1016/j.addma.2021.102386
Keywords
open lattice structure, lattice skin, digital light processing (DLP), printable relative density, functional grading
Citation
Woodward, Ian R., and Catherine A. Fromen. “Scalable, Process-Oriented Beam Lattices: Generation, Characterization, and Compensation for Open Cellular Structures.” Additive Manufacturing 48 (December 1, 2021): 102386. https://doi.org/10.1016/j.addma.2021.102386.