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.
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.
- Tensile structures.
- 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
Take a look back at our top 5 interviews of 2017.
UandI announce a new joint venture to deliver a new Designer Outlet shopping destination in Cannock.
"A wilful misuse of public funds" - MPs committee calls for legal action against HS2 Ltd. for unauthorised redundancy payouts.
Do you know the difference between these key legal terms?
The government has issued advice for building owners about external wall systems that do not incorporate ACM cladding.
Choosing the right engineering path is a 'daunting process' - BSRIA launch a new publication Inspiring Tomorrow's Engineers.
Memorial service held marking six months since the tragedy, as government faces criticism over rehousing progress.
A case study of Streamline House, the winner of the 2016 Alan King Award for Excellence in Architectural Technology.
At their annual conference, Constructing Excellence call for a radical digital transformation in construction.
Do you know your bulldozer from your roller? Find out about the different types of construction plant here.
Watch this video of construction CEOs explaining what they expect the role of humans in the future of construction will be.
Work is underway on Mjøstårnet in Norway, which could become the world's tallest timber building.