01 structural principlesmembranes

Structural Principles

of Membranes

IMS e.V. Institute for Membrane and Shell Technologies e.V.

Associated Institute of the Anhalt University of Applied Sciences, Germany

www.ims-institute.org

Hanging loads on a cable will give

such a shape.

The cable will pull on the anchoring

hooks.

- Structural principles of membranes-

Upwards pulling forces will create the

same shape in the opposite direction.

Ceno Tec

For stabilizing a whole surface we have to apply

this principle on every point of the surface.

Now the three-dimensional counter curved

surface is created.

In scientific terms it is called “Anticlastic Shape”.

The result shows that to be able to

fix a point three-dimensionally, we need

4 opposite anchoring directions.

- Structural principles of membranes -

Ceno Tec

High sag => little force


ISIMEM

The more flat, the higher the forces;

especially to counter the deflection of loads in textiles!


ISIMEM

In order to find a shape we have to introduce the principle of

Prestress;

with this approach we can find a shape……

His process we call :

Formfinding.

This process is unique for membrane structures.

Ca

ble

E

dg

e -

flex

ible

-

Be

am

E

dg

e -

rigi

d -

Fo

rm

Saddle Shape Conical Shape

Wave Form

valley and ridge

cable

Arch Pneumatics

Basic Forms

Anticlastic Synclastic (counter curved) (curved in the same

radial direction)

typical for: typical for:

- Saddle Shape (Hypar) - Pneumatics

- Conical Shape

- Wave Form

- Arch Form

Antiklastic / Synklastic Shape

Saddle Shape/Hypar




• Simple Hypar

• Saddle Shapes with more than 4 corner points

• Addition of Saddle Shapes

Saddle Shape/ Hypar

The Saddle Shape always has an anticlastic form, it is curved in two

directions. So downward curve (warp direction) can take the upward

wind load, while the upward curve (weft direction) can bear

downward loads like rain or snow.

Simple 4 point-hypar with edge cables source: www.mehler-texnologies.com

Saddle Shape/ Hypar

Simple 4-point-hypar with beam edge Wertkauf, München

source: „Textiles Bauen“ by Stromeyer

Saddle Shape/ Hypar

Examples for mixed edges: cables and beam

Two beam edges, two cable edges One beam edge, three cable edges

Saddle Shape/ Hypar

Examples for mixed edges: cables and beam

source: www.schmitz-peter.de

Yard cover Sun sail for a balcony

source: www.schmitz-peter.de

Hypar: symmetrical, two masts

Saddle Shape/ Hypar

Hypar: with only one mast

Hypar: hung up on building and one mast

Saddle Shape/ Hypar

The Influence of the Curvature

strong curvature

less curvature

hardly any curvature – danger of watersack

Saddle Shape/ Hypar

Other Examples for 4 point-hypars

Garden pavillons

source: www.news-shadesasia.com

source: www.news-shadesasia.com

Saddle Shape/ Hypar

Other Examples for 4 point-hypars Art sculptures

Fabric Structures in Urban Setting, UK

source: “Fabric Structures” by Samuel J.Armijos

Tsunami Shade Structures,


Saddle Shapes/Hypar




With more than 4 corner points

Saddle Shape/ Hypar

6-corner points: 2 high points, 4 low points

Tent for the TCP Ministry, Brunei, source: www.sl-rasch.de

Saddle Shape/ Hypar

Shopping Mall, Luxemburg, source: www.ceno-tec.com

10-corner points:

6 high points, 4 low points

Saddle Shape/ Hypar

Lotus Flower, by G.H. Bruce,


8-corner points: 6 high points, 2 low points

Saddle Shape/ Hypar

Other Examples for Hypars with more than 4 corner points

source: www.tensinet.com

Roof over Architecture Office Willy van der Meeren,1969,


Thowal Tents, 1990, Jeddah, Saudi-Arabia

Examples for Additions




Saddle Shapes/Hypar

Saddle Shape/ Hypar

Addition of Saddle Shapes - Examples

Hypars with cable edges lined up Circular addition of hypars with beam edge

Saddle Shape/ Hypar


Lined up hypars with cable edges source: www.shadestructuresperth.com

Saddle Shape/ Hypar


Circular addition of hypars

Gesundbrunnen Köln, Germany, Frei Otto,

source: www.upload-wikipedia.org

Saddle Shape/ Hypar


Lined up hypars, beam edges over the arches, cable edges at the sides


Wave Form




Wave Form

A wave shape will be formed by load bearing cables and tensioning

cables placed in parallel planes over and under a membrane surface.

Connection cable elements help to stabilize the system.

Wave form with cable edges Wave form with beam edges

Wave Form

Wave form with beam edges Swimming Pool Roof, Aigua, Maldonado, Uruquai,

source:www.tensinet.com

Wave Form

Wave form with cable edges forming a garland boundary

Brisbane Expo Pavillon, 1988, source: www.flickr.com

Wave Form Other Examples

Seville Olympic Stadium

Wave Form Other Examples

Okayama Dome, Japan, source: www.makukouzou.or.jp

Conical Shapes




• Examples for different Floor Layouts

• Different Highpoint Solutions

• Examples for different Mast Solutions

• Additions of Cones

• Umbrellas

Conical Shape

The conical shape always has an highpoint (internal point) situated

above the plane with the basic form outerline. Again, this shape has a

double curvature. The radial lines bear outside loads while the

horizontal lines can take the loads from inside (e.g. wind)

The high point can be supported by inner or outer mast elements.

Conical shape with cable edges and

6 low points in the basic shape

outerline

Conical shape with beam edges and

6 low points

Conical Shapes




Examples for different Floor Layouts

Conical Shape Different Floor Layouts

Conical shape with circle-shaped floor layout (rigid clamped ring)

Public Space Zellik, Belgium, source: www.tensinet.com

Conical Shape

Right angle floor layout

Octagonal system


Conical Shape

Conical shape with right-angle floor layout source: www.fabritecstrucures.com


Conical Shapes




Different Highpoint Solutions

Conical Shape

Rigid clamped ring Eye loop

Suspended high point, garland edge Hump

Conical Shape Different High Point Solutions

Conical Shape

Rigid clamped ring

Saimekadin Amphitheatre, Turkey,


source: www.fabristructures.com


Conical Shape

Eye Loop

German Pavillion,

Expo Montreal 1967, Frei Otto

source: www.fabricarchitecturemag.com


Highpoint with garland-shaped cable edges


Showroom Pavilions, Leonberg, Germany,

source: www.sl-rasch.de

Suspended high point

source: www.fabritecstructures.com


Hump:

membrane stretched

over high point

Schlumberger Factory in Paris, France, 1985,



Conical Shapes




Examples for different Mast Solutions

Central mast

source: www.archiexpo.com

Conical Shape Different Mast Solutions

source: “Fabric Structures”

by Samuel J.Armijos

Inclined middle mast


Flying mast

Terme di Chianciano, Italy, source: www.tensinet.com


Conical Shape

Different Mast Solutions

Yokohama Exotic Showcase,

1989


Outside support

Conical Shapes




Additions of Cones

Conical Shape Additions of Cones

Right angle ground, joined

together, ridge cables become

necessary

Right angle ground, with free

edge cables, creating eyes in the

middle


Vrije Basisschool Bertem,

Belgium


Two high points


source: www.fabristructures.com Several high points arranged in a line


Several high points in one structure with cable edges


“Skysong” by FTL Design Engineering Studio, source: www.fabristructures.com

Several high points in one structure with inclined masts



Several high points in one structure

source: www.fabricstructures.com


Combination of alternating high and low points


source: www.2010shanghai.eu

Cone top ring as low point

source: www.fabricarchitecturemag.com

Shanghai World Expo Boulevard, China

Conical Shape Umbrellas

Umbrella, right angle,

beam edge

Umbrella, seven corners,

free edge


Umbrella, right angle, beam edge

IHK Würzburg, Germany,

source: www.kochmembranen.de


Umbrella, free edges

Conical Shape Addition of Umbrellas

Addition of umbrellas standing in a

line, connected, beam edges



Another example of an addition of

connected umbrellas

design by B.Eng. Yu Zhao, Archineer, Representative of the IMS in China.


Addition of

connected umbrellas



Shanghai Subway Station Line 6, China


Ensembles of free standing umbrellas, not joined



Convertible Umbrellas, Makkah and Obhur, K.S.A., source: www.sl-rasch.de



Umbrellas for the Hotel d ´Angleterre, Lausanne, Switzerland, source: www.sl-rasch.de


Free addition of umbrellas

Sun Protection System in Abu Dhabi, United Arab Emirates


Arches




Arches

Membranes connected to or pulled over arches have an anticlastic shape.

The arch will be strained by the membrane so it will have to be stabilized

by stay cables or the membrane, depending on the design.

Arch structure with one arch and cable edges for the membrane

Arches

Arch structure with one arch and cable boundary at the arch forming eyes between

the two membrane surfaces; eyes can be left as an open space or closed with

glass, membrane etc.

www.tensinet.com

Arches

Example for an arch structure with one arch and cable boundary at the arch

Cover of the Piazzale Italia, Italy,


www.tensinet.com

Arches

Arch structure with one arch

and beam edges for the mem-

brane

Addition of arch modules

with beam edges

Arches

Addition of modules with

square base and diagonal arch

Le Zenith, Paris, France,

source: www.tobydammit.com

source: www.textile-roofs.de

Arches

Arch structure with more than one arch – arches arranged in a line

Chemical Research Center, Venafro, source: www.eyekit.blogspot.com

source: www.eyekit.blogspot.com

Arches

Arch structure with more than one arch – arches standing in a row

Local Traffic Station, Puntigam, Graz, Austria, source: www.tensinet.com

Arches

Arch structure with more than one arch

Saga Headquarters, Sandgate, Kent, UK, source: www.tensinet.com

Arches Other Examples

Membrane between arches

“Wincor World”, 2005 Paderborn, Germany, source: www.technet-gmbh.de

Arches Other Examples

www.archiexpo.com

Pneumatics




• Cushion Structures

• Air Hall

• Other Pneumatic Structures




Cushion Structures

Pneumatics

Pneumatics - Cushions

Pneumatics are air supported constructions. Air is pressed between

two or more membrane layers to build up an internal pressure

keeping the system stable. The pressure has to be slightly above the

outer atmospheric pressure + loading forces from wind and snow.

Thus different shapes can be formed.

Cushion with square base

and beam edge

Cushion with circular base

and beam edge


Cushion roof structure

Swimming Bath „Rheinwelle“ Bingen, Germany

Dr. Krieger Architekten + Ingenieure GmbH & Co. KG, Form TL,

Ceno Tec GmbH, 2005

Pneumatics – Cushions

Modern Teahouse, Frankfurt, Germany, source: www.tensinet.com

Another example for a cushion structure


Cushions are synclastic structures, the surface is curved in the same

radial direction


Mixed shape: anticlastic cable structure with synclastic cushion “fillings”


Example for anticlastic cable structure with synclastic cushion “fillings”,

Design for a yard cover: Ministries Complex, Kuwait, done by IMS e.V.


Another example: structure consisting of several cushions

“Eden Project”, Bodelva, China


The load-bearing of the cushion

depends on the load direction.

Snow from above is taken by the

lower underside layer;

uplift wind from the upper layer.

Pneumatics




Air Hall

Pneumatics – Air Hall

Air Hall with circular floor layout

Air Hall with hexagonal floor layout

and air lock

In an air hall the whole inner space between ground floor and delimiting

membrane surface is filled with overpressure. Air Halls can only be

entered through air tight locks.


Airhall Bonn, Germany, source: www.kochmembranen.de

Example for an air hall with circular floor layout


Mobile Kitchen Monument, source: www.raumlabor.net

Mobile sculpture air hall

Pneumatics




Other Structures

Pneumatics – Other Structures

“Air- Forest” – art pavillon

www.spaziopubblicopalermo.org

Sculpture done by “Mass Studies”, Denver, USA,

source: www.air-mass.purzuit.com


Air Bubble Sculpture done by the Haus-Rucker-CO group,1972, source: www.klima-wandel.de


Vision of a “Grid Pavillon” with facade consisting of inflated membrane grid

Mobile Perfomance Venue, design:”Various Architects”, source: www.dezeen.com

• Formfinding process is needed to create a shape

• Anticlastic shape for mechanically prestressed structures

• Synclastic shape for pneumatic structures

• Spacial curvature ( synclastic, anticlastic) needs patterning

like tailoring of cloths;

• Change of shape under load ( large deformations) is a

loadbearing principle ( like trees in nature, eartquake

resistance);

• Compensation is needed for stressed structures.

• Erection requires the possibility of introducing stress and

anchoring of the resulting forces.

Principles of Tensioned Structures

01 structural principlesmembranes

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