Mark Tam and Caitlin Mueller present at RobArch 2016 in Sydney2016-03-18, Tags: fabrication 3d-printing additive-manufacturing principal-stress-lines
Digital Structures are at the 3rd Robotics in Architecture conference in Sydney, Australia to share their work on robotics-enabled stress line additive manufacturing, a new 3D printing technique that deposits material along lines of force flow for enhanced structural performance.
3D Printed Structures: Challenges and OpportunitiesCaitlin Mueller, STRUCTURE, 2016
Technologies for 3D printing, or more broadly additive manufacturing, have proliferated in recent years, and have captured the public’s imagination as a revolutionary way to democratize small-scale, customized manufacturing for the DIY community. In the design of buildings and bridges, 3D printing has proven to be a valuable technique for creating intricately detailed scale models in a fraction of the time required by traditional methods. In both cases, the generalized layer-by-layer material deposition process is a compelling way to achieve geometries of nearly infinite complexity with ease. But 3D printing has also permeated markets beyond the consumer and model scale, with increasing buzz about applying the technology to large objects, such as full-scale buildings. This prospect is exciting for several reasons: reduced construction waste through highly precise material placement, increased capacity for complex geometries for both functional and aesthetic purposes, and new possibilities for integrating building component functions into a single, streamlined assembly. Looking forward, it is clear that many challenges lie ahead before the promise of 3D printing can be broadly achieved for building structures, but the recent, rapid development of increasingly realistic proofs-of-concept is highly encouraging. The continued contributions of pioneering structural engineers are critical to help push this transformative technology from small-scale geometric representation to high-performance, full-scale structures.
Digital Structures heads to World Maker Faire in NYC2015-09-25, Tags: fabrication 3d-printing additive-manufacturing mars composites
Mitchell Gu, Caitlin Mueller, and team head to NYC as finalists in the NASA 3D Printed Habitat Challenge at the World Maker Faire. Our submission includes a 3D-printed model that makes use of four different additive manufacturing strategies, including a heat-formed thermoplastic composite shell.
Ouroboros: 3D-Printed Martian HabitatDesign, 2015
Ouroboros is an additive manufacturing and spatial concept for producing architectural-scale composite structures that are high-strength, light-weight, and air-tight—all from compounds present on Mars. A shared symbol of ancient cultures, the ouroboros is the idealized embodiment of metabolism; an infinite process of re-creation, of something beginning anew as soon as it ends. Today, the aspiration of the ouroboros persists as we seek to initiate a new and sustainable human culture of technology and design on Mars.
The Ouroboros habitat promotes a metabolic rhythm of activity reflective of its circular geometry and processing of materials. The proposed materials processing unit, 3D CNC loom, and pultrusion module apply emerging technologies to synthesize a pressurized and climate controlled living space from Martian resources. Martian soil and air are processed and transformed into glass and plastic fibers that can be woven and pultruded into a strong, airtight composite shell; integrating structure, insulation, air barrier, radiant heating, and ambient lighting, within a singular structural surface. Using a new approach for the additive manufacturing of structural composites, a CNC loom forms the thermoset textiles into a global toroidal shape by combining pultrusion with three-dimensional textile weaving. Structurally, the lightweight tensile shell of the habitat takes full advantage of the reduced Martian pressure and gravity, allowing for minimal material usage and maximal reconfigurability of the interior. Contributing novel approaches to structure, material selection, programmatic flexibility, and spatial experience, Ouroboros represents a revolution in current thinking in sustainable, architectural-scale additive manufacturing and design on Mars and beyond.
This design project is a submission for NASA's 3D-Printed Habitat Challenge, and was selected as a finalist to be presented at the NYC Maker Faire in late September 2015. More information and details about our proposal can be found here, and a gallery of all finalists is here.
Digital Structures Finalists in NASA's 3D-Printed Habitat Challenge2015-09-01, Tags: fabrication additive-manufacturing space-architecture mars composites
An interdisciplinary team of Digital Structures students, along with Justin Lavallee of the Architecture Fab Lab, are finalists in a NASA competition to design 3D-printed habitats for a 2035 Mars mission. Our submision will be presented at the World Maker Faire in New York on Sept. 26-27. More information about our design concept, called Ouroboros, and fabrication processes can be found here.
Characterization of anisotropy in fused deposition modeling 3D printingResearch, 2015 - Present
The layer-based technique of the fused deposition modeling (FDM) additive manufacturing process creates anisotropy within printed parts, but the full quantitative characterization of this anisotropy is not yet available, making it difficult to predict structural performance of printed parts. This research studies the tensile strength of ABS plastic created by FDM in incrementally rotated orientations, to analytically and experimentally characterize the anisotropy of the material. The known relationship between strength and orientation can then be used to create a predictive model of the local material behavior in any FDM printed object.
Structural lattice additive manufacturingResearch, 2015 - Present
The structural performance of traditional 3D-printed parts is typically limited by nature of the ayer-by-layer construction. Such parts are anisotropic due to decreased adhesion between layers and the internal structure is uniform, not flexible. This project seeks to overcome these limitations by printing along the edges of a stress-optimized lattice. With this approach, larger-scale, lightweight parts can be printed with an optimal structure that can vary depending on a loading configuration. The results of this project may be promising for diverse fields including concrete rebar design, spaceframe prototyping for buildings, and generative art.
The fabrication component of the project includes designing a custom extruder for a six-axis robotic arm that excels in printing along hard-to-reach toolpaths in free air, with larger nozzle diameters. To complement this technology, a computational tool is in development to generate lattices and toolpaths for any part and its loading configuration.
Additive manufacturing of structural prototypes for conceptual designCaitlin T. Mueller, Ali Irani, and Benjamin E. Jenett, Proceedings of the IASS-SLTE 2014 Symposium, 2014
Additive manufacturing, also known as 3D printing, is a powerful technique for quickly fabricating complex geometrical models. This paper investigates the potential of using this technique for producing structural prototypes, or models that can be used in conceptual design to understand and compare the structural behavior of design alternatives. The main challenge is the anisotropy of the printed parts, which exhibit significant reductions in tensile capacity when loaded across printed layers. This paper characterizes this challenge through experimental results, and proposes and tests several new techniques to address anisotropy limitations.
Prototyping 3D-printed structural connectionsResearch, 2015
This research studies the potential of fabricating structural connections additive manufacturing, or 3D printing. Unlike typical bolt-and-plate connections that are mass-produced from sheet material, 3D printed connections can have highly variable geometry due to its digital nature. This technology not only makes connection design and fabrication more accessible and flexible, but also asks us to reconsider the relationship between the connection, the connected parts, and the forces transferred between them. The ability of 3D printers to produce intricate parts with fine details makes it possible to produce connections that can wrap around connected members and transfer forces through surface texture induced friction. It also opens up the possibility of integrating snap-fit behavior into connection design to make assembly faster and easier. The research starts with connection geometry exploration, with a goal to parameterize form and link it to structure behavior. Parallel these efforts is connection prototyping using a range of digital fabrication techniques.
Stress line additive manufacturing (SLAM)Research, 2014 - Present
The project presents a new integrated software and hardware process that reconsiders the traditional addive manufacturing (AM) technique of fused deposition modelling (FDM) by adding material explicitly along the three-dimensional principal stress trajectories, or stress lines, of 2.5-D structural surfaces. Using a six-axis robotic arm, this project materializes continuous stress fields into discrete structural topologies, rendered computationally as robotic tool paths. The goal of this project is to develop and perfect this new technique, and to explore conditions in which it is favorable to conventional layer-based additive manufacturing. The research is supported by methodologies including computational structural analysis and comparative structural load testing. For more video information, see this YouTube video.
Robotics-enabled stress line additive manufacturingKam-Ming Mark Tam, Caitlin Mueller, James Coleman, and Nicholas Fine, Rob|Arch 2016: Robotic Fabrication in Architecture, Art and Design 2016, 2016 (In press)
The presented research uses a 6-axis industrial robot arm and a custom-designed heated extruder to develop a new robotic additive manufacturing (AM) framework for 2.5-D surface designs that adds material explicitly along principal stress trajectories. AM technologies, such as fused deposition modelling (FDM), are typically based on processes that lead to anisotropic products with strength behaviour that varies according to filament orientation; this limits its application in both design prototypes and end-use parts and products. Since stress lines are curves that indicate the optimal paths of material continuity for a given design boundary, the proposed stress-line based oriented material deposition opens new possibilities for structurally-performative and geometrically-complex AM, which is supported here by fabrication and structural load testing results. Called stress line additive manufacturing (SLAM), the proposed method achieves an integrated workflow that synthesizes parametric design, structural optimization, robotic computation, and fabrication.
Stress line additive manufacturing (SLAM) for 2.5-D shellsKam-Ming Mark Tam, Caitlin Mueller, James Coleman, and Nicholas Fine, Proceedings of the International Association for Shell and Spatial Structures (IASS) Symposium 2015, 2015
In the field of digital fabrication, additive manufacturing (AM, sometimes called 3D printing) has enabled the fabrication of increasingly complex geometries, though the potential of this technology to convey both geometry and structural performance remains unmet. Typical AM processes produce anisotropic products with strength behavior that varies according to filament orientation, thereby limiting its applications in both structural prototypes and end-use parts and products. The paper presents a new integrated software and hardware process that reconsiders the traditional AM technique of fused deposition modelling (FDM) by adding material explicitly along the threedimensional principal stress trajectories, or stress lines, of 2.5-D structural surfaces. As curves that indicate paths of desired material continuity within a structure, stress lines encode the optimal topology of a structure for a given set of design boundary conditions. The use of a 6-axis industrial robot arm and a heated extruder, designed specifically for this research, provides an alternative to traditional layered manufacturing by allowing for oriented material deposition. The presented research opens new possibilities for structurally performative fabrication.