Space frame

Simplified space frame roof with the half-octahedron highlighted in blue

A space frame or space structure is a truss-like, lightweight rigid structure constructed from interlocking struts in a geometric pattern. Space frames usually utilize a multidirectional span, and are often used to accomplish long spans with few supports. They derive their strength from the inherent rigidity of the triangular frame; flexing loads (bending moments) are transmitted as tension and compression loads along the length of each strut.

Most often their geometry is based on platonic solids. The simplest form is a horizontal slab of interlocking square pyramids built from aluminium or tubular steel struts. In many ways this looks like the horizontal jib of a tower crane repeated many times to make it wider. A stronger purer form is composed of interlocking tetrahedral pyramids in which all the struts have unit length. More technically this is referred to as an isotropic vector matrix or in a single unit width an octet truss. More complex variations change the lengths of the struts to curve the overall structure or may incorporate other geometrical shapes.

Space frames were independently developed by Alexander Graham Bell around 1900 and Buckminster Fuller in the 1950s. Bell's interest was primarily in using them to make rigid frames for nautical and aeronautical engineering although few if any were realised. Buckminster Fuller's focus was architectural structures and has had more lasting influence.

Space frames are an increasingly common architectural technique especially for large roof spans in modernist commercial and industrial buildings.

Notable examples of buildings based on space frames are:

• Stansted airport in London, by Foster and Partners
• I. M. Pei's Bank of China Tower and the Louvre Pyramid
• Rogers Centre by Rod Robbie and Michael Allan
• McCormick Place East in Chicago
• Eden Project in Cornwall, England
• Globen, Sweden - Dome with diameter of 110 m, (1989)
• Biosphere 2 in Oracle, Arizona

Larger portable stages and lighting gantries are also frequently built from space frames and octet trusses.

Tubular space frames are also widely used in the production of modern motorcycles and automobiles, but monocoque car bodies have been more common since the 1950s. Most purpose built race cars used in sports car and stock car racing use tube frame chassis. Spaceframes have also been used in the latest incarnations of the unorthodox bicycles designed by Alex Moulton. The first automotive aluminum space frame appeared on the Honda NSX, other examples include the Audi A8, Caterham 7, Ferrari 360, and Lamborghini Gallardo.

In February 1986, Paul C. Kranz walked into the U. S. Department of Transportation office in Fort Worth, Texas, with a model of an octet truss. He showed a staff person there how the octet truss was ideal for holding signs over roads. The idea and model was forwarded to HQ USDT in Washington, D. C. Today, the octet truss is the structure of choice for holding signs above roads in the United States.

External links

Academic Links

• University of Surrey - Space Structures Research

Informational Links

• Uskon Space Frames
• www.archistructures.org
• www.buschindustries.com
• www.deltastructurescom
• www.mero.de
• www.novumstructures.com
• octet truss 3D animation
• (English)Aluminum alloy spaceframe
• (Italian)Strutture Reticolari in Alluminio

See also

• Platonic solids
• Body-on-frame
• Monocoque
• Backbone chassis