What is membrane structure in building construction?

Membrane structures are spatial structures made out of tensioned membranes. The structural use of membranes can be divided into pneumatic structures, tensile membrane structures, and cable domes. In these three kinds of structure, membranes work together with cables, columns and other construction members to find a form.

Want more information on membrane structure buildings? Feel free to contact us.

Membranes are also used as non-structural cladding, as at the Beijing National Stadium where the spaces between the massive steel structural members are infilled with PTFE coated glass fiber fabric and ETFE foil. The other major building on the site, built for the 2008 Summer Olympics, is the Beijing National Aquatics Center, also known as the Water Cube. It is entirely clad in 100,000 square metres of inflated ETFE foil cushions arranged as an apparently random cellular structure.

Materials

[

edit

]

The common membranes used in membrane structures include:

• PVC coated polyester fabric
• Translucent Polyethylene fabric
• PVC coated glass fiber fabric
• PTFE coated glass fiber fabric; foils like
• ETFE foil
• PVC foil.

Gallery

[

edit

]

Conference

[

edit

]

The International Centre for Numerical Methods in Engineering (CIMNE) in Barcelona biannually holds the international conference Textile Composites and Inflatable Structures (Structural Membranes).[1] The conference has been taking place in Barcelona, Stuttgart and Munich. The tenth edition of the conference will be organized in 2021 in Munich.[2]

Literature

[

edit

]

• ETFE, Technology and Design, Annette LeCuyer, Verlag Birkhäuser, ISBN 978-3-7643-8563-7
• Membrane Structures, Hrsg. Klaus-Michael Koch, Verlag Prestel, ISBN 978-3-7913-3049-5

See also

[

edit

]

References

[

edit

]

Contact us to discuss your requirements of steel curtain wall system for sale. Our experienced sales team can help you identify the options that best suit your needs.

Membrane structures are a term commonly used to refer to the design of roofs using a membrane attached to steel cables. Their main characteristics are the way they work when stretching, their ease of manufacture, their ability to cover large spans and their flexibility. This structural system requires a small amount of material thanks to the use of thin canvases, which, when stretched using steel cables, create surfaces that can overcome the forces imposed on them.

Mainly used in the coatings of sports centers, arenas, industrial and agro-industrial structures, stretching structures are based on old systems used during the Roman Empire. However, from the Roman period to the mid-20th century, due to low demand, convenience of use and lack of manufacturers of structural elements and compounds capable of resisting the created forces, they technically almost did not develop. It was only after the Industrial Revolution that new developments emerged that were able to re-create demand for tent systems. Their advantages are the low cost of mass production, the ability to adapt to a variety of structures with large spans, such as circus tents.

There are three main types of stretching systems for membrane structures:

1. Structures with membrane tension. Here the membrane is held by cables, which allows to distribute stretching voltages through its own form.

2. Stretched nets. Structures in which a grid of cables carries internal forces, transferring them to individual elements, such as sheets of glass or wood.

3. Pneumatic structures. Here the protective membrane is supported by air pressure.

Constructively, the system forms by combining three elements: membranes, rigid structures such as poles and masts, and cables.

The membranes of polyester fibers with PVC coating have great ease in production and installation at the plant; Lower cost and the average durability is about 10 years.

Covered on the basis of fiberglass membrane has excellent strength - about 30 years; and greater resistance to adverse factors (sun, rain and wind); however, they require skilled labour.

There are two types of support in membrane systems: direct and indirect. Direct supports are those in which the construction is arranged directly on the ground part of the construction structure. Indirect support is when the hull is arranged from a raised point, such as a mast.

The cables, which are responsible for the distribution of stretching stresses and strength, are classified in one of two ways according to the function they perform: carrier and stabilizing. Both types of cables intersect orthogonally, providing strength in two directions and avoiding deformations. Carrier cables are those that directly accept external loads located at the highest points. Stabilizing cables are responsible for strengthening the carrier cables and their mutual attachment. You can avoid attaching stabilizing cables to the ground with a peripheral fastener.

Also, the cables have their own item according to their position: the cable of the rib line belongs to the top rope; While the ropes of the Enda are fixed below all others; radial cables are stabilizing rings. The cables with the ribbed line support gravitational loads, while the Ropes of the Enda support the wind loads. 

Here are some examples of buildings where membrane structures are used.

1. Tent House in Australia

Here the membrane roof serves as a tent and covers the box of the house, taking on heat loads. The free space between the roof and the wall creates a simple ventilation process. gravitational loads, while the ropes of the Enda support wind loads. 

2. Center of the Arts in Taiwan.

The art center has open spaces for recreation, covered by a membrane structure, between the four main volumes - theaters, an exhibition hall, an art library and an educational center. Wide holes in the roof direct water into the patio, so warm air rises up creating good conditions for air conditioning.

3. United Nations in New York

The design of the canopy for the roadway in the form of spiral arcs, which have a wavy shape and twisted along the length with minimal anchorage points, has been developed. The design has a modular system, using prefabricated steel farms, which are characterized by rapid installation. The high-tech textile membrane performs two functions: provides support as a working element of stretching, evenly distributes loads and lets in sunlight to naturally illuminate the space below. The structure uses two types of fabric: a glass fabric with teflon coating as the main, and a glass fabric with a silicone coating for greater transparency in the design of the arches. Functionally, the canopy provides parking for motorcades as they load and unload delegates, requiring ventilation for cars inside idling. The open facades and air vents that run along the entire length of the farms allow the air to circulate freely throughout the hull.

4. King Fahd National Library in Saudi Arabia

The facade has a diamond-shaped textile shed that can be opened and closed. Inserted white membranes, supported by a three-dimensional structure of a steel tether with stretching, act like sun umbrellas. At night, the facade glows with changing colors and becomes the cultural beacon of the city.

At outdoor temperatures of up to 50 degrees Celsius, the membrane facade, which has been optimized for the local movement of the sun with a sophisticated 3D refraction of light, combines the necessary sun protection with maximum light penetration and Transparency.

This facade is combined with the ventilation and cooling of the building through multi-layered air conditioning and floor cooling. 

5. Indoor rooftop pool in Germany

The pool covers the structure, consisting of a pre-stretched membrane on three high points and a side mount. To provide effective protection from prying eyes, the roof of the membrane leans on the longest axis, forming an extreme geometric shape: the design consists of very steep and very flat areas, which creates a particular problem because of the winter Snow. In addition, organically formed rings with a high point around the mast are ideally geometrically integrated into the double curved surface of the membrane. Since the structure was created on the existing old building, it was necessary to exercise caution when placing support points.

6. Bar restaurant in the Maldives

Unlike other buildings on the island, thanks to the interesting design and height of 23 meters, this structure dominates the island. Instead of traditional natural materials, monolithic reinforced concrete was used in the construction of the building; it is made of a supporting, round in the plan, a wall around which is a console spiral staircase of prefabricated elements. The entire outer structure is veiled into a light grey translucent membrane. 

If you want to learn more, please visit our website What is a space frame structure.