Inter-species Optimization for the Construction of Wooden Spatial Structures

Nathan King and Gustav Fagerstrom

 

The United Nations estimates that the global demand for wood products will double in the next 15 years. At the same time increased environmental regulations, degraded resources, and regionally antiquated forest management policies are projected to decrease the capacity of the global supply chain. Globally, emerging building codes and technologies are providing new opportunities for the use of wood while increased concerns over supply chains and lifecycle costs are bringing about a renewed call for the use local materials and methods. Computer-aided design, manufacturing, and engineering (CAD/CAM/CAE) technologies are increasingly integrated into many aspects of design and construction, have been deeply embedded in today’s architectural discourse, enabled new modes of practice, and informed design pedagogy on a global scale.

 

Within the context of wood material systems, emerging computational design and fabrication technologies present new challenges and opportunities. Wood is an Orthotropic – also known as anisotropic – material and exhibits different behavior in different directions. This behavior presents a challenge for engineering design but also, in the context of computational design, represents an opportunity for advanced structural performance optimization. Beyond anisotropic behavior, wood also exhibits a diversity of characteristics between species. From tensile, compressive and bending strength, to moisture absorption and specific density—each species exhibits different performative properties. In addition to inter-species property variation, the processing of timber into lumber induces additional performance parameters and the degree in which grain types—tangential, end, or radial—are exposed can have drastic influence on material behavior. These factors, when explored through the lens of computational workflows and robotic fabrication, present interesting and relatively unexplored opportunities. In the design of structural systems, member size often varies as load cases and performance demands change. In recent years, Additive Manufacturing (AM) and topological optimization techniques have aligned with the perceived demand for, and the promise of, technically feasible infinitely customizable cellular structure and ushered in new paradigms in AEC related material and process research. But what about wood?!

 

This research proposes an exploration of the potential of inter-species optimization for the construction of spatial structures. Through the design, optimization, analysis, assembly, and evaluation of a prototypical multi-species hybrid spatial structures the research explores new potential for computational design in wood material systems while presenting a microcosm for the broader context of functionally gradient materials in buildings.

 

Acknowledgements:

This research is an extension of research and  that was conducted with the support of Autodesk, the Autodesk BUILD Space; Virginia Tech College of Architecture and Urban Studies, Center for Design Research, MASS Design Group, and The Institute for Creativity, Arts, and Technology; the Rose Fitzgerald Kennedy Greenway Conservancy; The United Nathans; and Rudabega. Project collaborators include Adam Allard, Alan Ricks, Ashleigh Otto, Brendan Kellogg, Chip Clark, Cole Smith, Conor Byrne, David Barrett, David Scurry, Ed Coe, Giorgia Cannici, Gustav Fagerstrom, Jason Zawitkowski, Jeff Snyder, Jonatan Anders, Jonathan Rugh, Justin Lavallee, Kyle Barker, Mark Leach, Martin Philipp Angst, Michael Murphy, Mike Steehler, Nathan King, Nathan Melenbrink, Nick Cote, Nikki King, Paul King, Robert Dunay, Steve Bickley, and Victoria Smith.  Mike Dewberry, Matt Jezyk, Ian Keough and others contributed to the development of the Dynamo-to-robot workflow.

 


1 This research will be advanced during four-day workshop “LOG JAM! Polar Orthotropy and Principle Stress”, as part of the international SmartGeometry2016 conference in Gothenburg Sweden hosted by faculty Nathan King and Gustav Fagerstrom.

2 Estimates derived from the report from the Food and Agriculture Organization of the United Nations, “State of The Worlds Forests 2009”

 


 

Nathan King is an Assistant Professor of Architecture at the School of Architecture + Design at Virginia Tech and has taught at the Harvard University Graduate School of Design (GSD), The Rhode Island School of Design (RISD), and the University of Innsbruck. With a background in Studio Arts and Art History, Nathan holds Masters Degrees in Industrial Design and Architecture. He earned the degree Doctor of Design from the Harvard GSD where he was a founding member of the Design Robotics Group with a focus on computational workflows and Additive Manufacturing and Automation in Architecture, Engineering, and Construction industries. Beyond academia, King is the Director of Research at MASS Design Group, where he collaborates on the development and deployment of innovative building technologies, medical devices, and evaluation methods for global application in resource-limited settings. As technology and programs consultant, Nathan collaborated on the design, development, and launch of the Autodesk BUILD Space—BUILD for Building, Innovation, Learning and Design—which is a world class collaborative AEC research facility in Boston MA scheduled to open in May 2016.