Opportunities and Challenges of Robotically Assisted 3D Printing of Shell Structures
Abstract
Understanding the interdependency of design, material, fabrication process, and environmental stimuli in large-scale Additive Manufacturing (AM) processes is significant. This study aims to assess the potential and limitations associated with robotically assisted AM of scaffold-free shell structures at macro- and meso-scales. A workflow consisting of four steps (design, fabrication, digital reconstruction, and digital and physical analysis) was developed to study the impact of three process parameters (L, the distance between hypothetical nodes on the toolpath, H2, the standoff distance of the nozzle, and T, the delay time at each point) on the interlayer bond strength of 3D printed structures with a clay-based material.
This paper proposes a technical approach by manipulating process parameters that alter the geometry of the layers on the meso-scale to emulate densification and to enhance friction between consecutive layers in robotically assisted paste AM processes. The difficulties related to simulating and predicting AM processes in a digital analysis method are described, as are results from the standard flexural test performed on 95 printed specimens. Flexural tests showed that manipulating the H2 parameter based on the defined criteria improved interlayer bond strength under shear by 41.2% on average. Since the results are inconsistent, however, it was not possible to detect any obvious impact of the T parameter on interlayer bond strength.
Additionally, this dissertation delves into the details of a nested robotic fabrication strategy at the macro-scale and discusses the design requirements for constructing structures taller than the robot's maximum reach. According to the specified design requirements, a case study was carried out in order to explore the possibilities and challenges associated with constructing stackable geometries using nested 3D printing. Clay was utilized for the first time in a robotic AM process to create a dissolvable formwork. This research highlights the need to integrate cutting-edge technological considerations into the design process, which can lead to design innovations and structural integrity.
Subject
Architectural RoboticsRobotic Fabrication
Additive Manufacturing
Clay 3D Printing
Concrete 3D Printing
Nesting
Stackable Geometry
Citation
Farah Bakhsh, Mehdi (2021). Opportunities and Challenges of Robotically Assisted 3D Printing of Shell Structures. Doctoral dissertation, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /196291.