Print-Path Orientation as a Designable Structural Parameter in Large-Scale Robotic 3D Printing
Description
Additive manufacturing in building construction can be extended for mass customization of building components or even complex mold making. This study examines the process parameters of raster orientation of short carbon fiber-reinforced polylactic acid (SCF-PLA) and neat PLA in large-scale 3D printing. Three raster orientations (unidirectional, cross-ply, and quasi-isotropic layups) were printed using a pellet extruder assembled on an industrial robotic arm. Tensile and flexural tests were conducted by Dr. Ji Ma to characterize the differences between SCF-PLA and neat PLA across all raster orientations. This study shows that neat PLA has higher tensile strength compared to SCF-PLA, and quasi-isotropic orientation can improve the weak mechanical properties of both SCF-PLA and PLA. This research highlights the interface bonding challenges encountered with larger 3D printed filaments, which result in more significant pores. Furthermore, any factor that modifies rheological properties of the filament, such as carbon filling, can lead to a higher likelihood of material defects. To understand this discrepancy, microstructure analyses were conducted on intact and fractured 3D printed samples, including the analysis of micro voids, interlayer voids, and bonding between SCF and the PLA matrix. This suggests that the effects of quasi-isotropic layups can be applied to enhance 3D print large-scale polymer-based building components.
This research was published in Additive Manufacturing Letters.
Venue
Additive Manufacturing Letters (2025)
Role
Project Lead, computational design and robotic fabrication
Design Method
Computational Design (Raster Orientation as a Designable Toolpath Parameter: unidirectional, cross-ply [0°/90°], quasi-isotropic [0°/60°/90°]) with Rhino/Grasshopper
Fabrication Process
Additive Manufacturing (Large-Scale Polymer Extrusion), pellet extruder on an industrial robotic arm; test specimens waterjet-cut to dimension
Building Material
Polymer Composite (SCF-PLA); neat PLA
Project Team
Ehsan Baharlou; Dr. Ji Ma
Student Research Assistants
Tabi Summers; Ipsita Datta
Image Credit
Ehsan Baharlou, CT.lab, University of Virginia, 2024
Acknowledgements
Support from Melissa Goldman, Dr. Trevor Kemp, and Joe Thompson at the University of Virginia’s Fabrication Facilities and Nanomaterials Characterization Laboratory.