Tensile surfaces, that is, surfaces which carry only tension and no compression or bending, rely on double curvature for their stability. Stability is provided by the opposition of two curvatures which enable the surface to be tensioned without losing its form.
Tensioning the surface reduces its elasticity and so its tendency to deform under load, and the curvature itself means that the surface will deform less for any given extension.
Tensile surfaces can be used in buildings to create thin, long span enclosures, such as roofs for sports stadia, shopping centres, atria and so on. Typically they are constructed using a PVC coated polyester or PTFE coated glass fabric, typically just 1 mm thick.
Double curvature can be anticlastic or synclastic.
Anticlastic surfaces are those in which the centres of curvature are located on opposing sides of the surface. This is commonly-described as a saddle shape. A hyperbolic paraboloid is an anticlastic surface.
Synclastic surfaces are those in which the centres or curvature are on the same side of the surface. This is a dome-shape. This can be created with an architectural fabric by inflation – that is, air pressure within the dome maintains the form of the surface when it is tensioned, rather than the opposition of the curvatures.
 Related articles on Designing Buildings Wiki
- Barrel vault.
- Biaxial bending.
- Concept structural design of buildings.
- Conoid shell.
- Fabric structures.
- Hyperbolic paraboloid.
- Limit state design.
- Structural engineer.
- The development of structural membranes.
- The structural behaviour of architectural fabric structures.
- Types of dome.
 External references
- ‘How structures work: Design and behavior from bridges to buildings’ (2nd ed.), YEOMANS, D., Wiley (2016)
Featured articles and news
BSRIA publish mechanical and electrical maintenance customer satisfaction key performance indicators.
Have a look at our article on the history, practice and techniques of placemaking.
Have a look at the key recommendations from ICE's new report on the digital transformation of infrastructure.
The Gate of Europe, the world's first inclining high-rises, with a lean of 15-degrees.
Why engineers need to keep pace with the challenges and opportunities of the digital transformation of the infrastructure sector.
Have a read of our introductory article on fabric structures; their history, properties and characteristics, and more...
Growing connectivity and what it means for physical infrastructure, disruptive new tech and increasing interdependencies.
Foster & Partners selected as architectural team for new bridge crossings in Ipswich.
Could this strange new concept be the future of skyscraper design?
Designing Buildings Wiki attended a RIBA panel debate on one of London's most notorious planning disputes.
Creating an accessible and inclusive environment – CIC publish new guide.
BRE report on the second day of MIPIM 2017.
Read about the 'Exceptional' sustainable design features of the recent winner of the coveted Your BREEAM Award.