The document provides an overview of lightweight membrane structures and their design processes, emphasizing the importance of pre-stressing and form-finding in achieving structural stability. It discusses different shapes and materials available for membranes, as well as the benefits of textile architecture, such as natural light transmission and flexibility. Finally, it outlines essential considerations for design, construction, and material selection necessary for effective and economically viable membrane projects.

1. ‘MEMBRANE’S’IN
LIGHTWEIGHT AND
MEMBRANE STRUCTURES
AR.SUVARNA LELE
ER.SHIREESH PATIL
CHAUGULE PATIL CONSULTANTS P
LTD
Guimarães, Portugal – 21-23 July 2010

2. MEMBRANE’S IN LIGHT WEIGHT AND
MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Introduction
Tensile structures
They are Light weight as their structural stability is derived from their pre
stressed shape rather than the mass of material used .
Tensile structures allow larger spans with easier and cheaper constructions
and they cover vast expanse of spaces.
Membranes are uniform in thickness with a capacity to support imposed
loads due to their designed shapes and deflections.

3. MEMBRANE’S IN LIGHT WEIGHT AND
MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
The aim of this paper is to take an overview of the ‘Membranes’ in cable
and membrane structures.
Before installation on site a membrane has to go through several stages
right from design including the steps as form finding, load analysis and
design of fabric geometry.
The paper also talks about several shapes and forms a membrane can
achieve and the principle behind the design of these shapes.
Important aspect of membrane structure is availability of membranes in
market. This paper accounts various available covering materials in the
market and the criteria have to be considered before their installations on
the site.

4. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
BASIC SHAPES AND FORMS
Synclastic surface .( fig 1) Anticlastic surface .(fig 2)
Membrane structure depends on double curvature to resist the imposed loads. The
shapes can be deciding factor of resistance of loads. The surfaces can be categories
in Synclasic and Anticlasic surfaces.
1]Synclastic surface: Upward loads are resisted by a stress increase about both axes
of the fabric while downward loads are neutralized by internal pressure. Inflatable
fabric structures are simplistic forms.( fig 1)
2]Anticlastic surface: Fibers with convex curvature. One surface resists the upward
load by increasing tension, while fibers with concave surface increase their tension to
resist downward loads.(fig 2)

5. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
BASIC SHAPES AND FORMS
The basic forms of all curvatures are hyperbolic paraboloids, cones or arches
Hperbolic
Paraboloid Cone Arch
thread in tension changes conventional materials Curvature provides
geometry when in in tension and resistance to out of
Compression. compression. plane forces.
Tension conditions between tensile and conventional materials

6. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Evolution Of Several Forms From The Basic
Add your text
6 point membrane Chinese hat Center arch
Rectangular pneu 3D node Custom2
Custom1
Rhino design
Some More Shapes
(www.membranes24.com)

7. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Add your text
Inflated bubble
Some More Shapes

8. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
DESIGN PROCESS
1.The first step in designing a fabric structure is to create a form with sufficient
PRE-STRESS or tension. Fabric structures must be clamped to a frame or be
pre-stressed in order to avoid “fluttering” like a flag or sail.
2.The second step is to DETERMINE THE BOUNDRIES of the tensioned fabric.
Boundaries include frames, walls, beams, columns and cables. The fabric is either
continuously clamped to frames, walls or beams or attached to columns with membrane
plates with adjustable hardware. In most cases the fabric forms a curved edge or
“CATENERY” between connection points requiring a cable, webbing belt or rope to
carry loads to the major structural points.
3.Once the primary points have been determined, the third step is referred to as
“FORM FINDING”. Form finding is the art of discovering the most efficient structure
which can be fabricated with as little waste as possible and can be transported and
installed with ease, installation and fabrication.
4.The last step in the design process is ANALYSING the structure’s response to
loads, including dead loads and live loads (snow, wind, etc.).

9. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE,
ER SHIRISH PATIL
Flowchart :Illustrating
General Approach to Tensile
Membrane Structure Design
and Engineering
Add your text

10. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Tensile membranes design process, from conception to realization
Add your text
Architects
Requirements
Conception
Construction,elevation
Form Finding
Membrane cutting and
manufacturing
Analysis
Cutting pattern
Detailing generation
Engineers
Contractors,Manufacturers.

11. MEMBRANE’S IN LIGHT WEIGHT AND
MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Hybrid Method Proposed for Tensile Membrane Design
Grid Generation Form Finding Surface Fitting Render
(a) Grid Generation, (b) Form finding (c) Surface fitting, (d)Render
representation
Representation of a membrane structure with a nodal force using a 5x5 grid

12. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
FROM CONCEPT TO SITE
1.SKETCHING.
2.COMPUTER DRAWING
3.PHYSICAL MODELLING
4.ACTUAL SITE
INSTALLATION
http://fabricarchitecturemag.com/articles/0708_rv2_rhino.html

13. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Form-finding
1.Soap and liquid plastic films: soap and liquids are excellent mediums to
experiment with as they exhibit excellent tensile capacity but lack shear
capacity. Wire or strings can act as cables and liquid as well as soap films
will form anticlastic shapes of pre stressed structures. The film or bubble
can be stretched to the limits till it breaks. Various shapes which are
formed after stressing the film can be noted and applied for further design.
2.Physical models Building:plays a significant part in design of structure.
The limitations and possibilities can be worked out by experimenting on
the physical models. The miniature model must carry or be identical with
the actual structure in properties. The structures are to be designed to be
in equilibrium conditions for applied loading conditions. The structures
mostly are designed to carry uniform pre stress in their membranes
Experimenting on physical models for evolution of different forms

14. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Add your text
Actual cutting process

15. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
TECHNICAL TERMS IN DESIGN OF TENSILE STRUCTURES
Base Fabric: The uncoated fabric, also known as greige goods.
Bias: Oriented at 45 degrees to the warp and fill directions of the fabric.
Add your text
Biaxial: Taken along two concurrent orthogonal directions, usually principal
directions.
Butt Seam: Seam created when the two pieces of fabric being joined together
are butted together with a strip twice the width of the seam.
Catenary Cable Pocket: Edge treatment in which the fabric is folded over
on itself to form a pocket in which a catenary cable can be installed.
Catenary Cable Fitting: Device attached to the end of a cable to allow a
connection to another member. Fittings are swaged.
Catenary: The curve theoretically formed by a perfectly flexible, uniformly dense fabric.
Catenary Cable Fitting: Steel cables that run through the pockets on the
perimeter of a tension fabric structure. The shape of the cable follows
that of the pocket, which is typically curved with a ratio of 1:10.
The length of the cable is determined by the project engineer supplying
the fabric patterning. The thickness of the cable is determined by the
engineer who calculates the reaction loads at the cable ends.
Coating: A material applied to a fabric for waterproofing and protection of
the fabric yarns.
Coating Adhesion: Strength of the bond between the substrate of a fabric
and the coating.

16. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
TECHNICAL TERMS
Compensation: The operation of shop fabricating a fabric structure of pieces
of the structure smaller in the unstressed condition than the actual installed size, to
Add your text the stretch at pre-stress level.
account for
Elongation: The change in lengths of a material sample; normally this is
associated with some load or force acting on the sample. In fabric, this elongation. does
not normally refer to true strain of the fiber elements as in the classical sense; but,
rather, normally refers to the apparent” strain resulting from a straightening out of the
crimped yarns in the fabric matrix.
Equilibrium Shape: The configuration that a tensioned fabric surface assumes when
boundary conditions, pre-stress level, and pre-stress distribution are defined.
Fabric Clamp: Device for clamping the edge of a fabric panel, usually a bar or channel
shape and made of aluminum or steel.
Form Finding: The process of determining the equilibrium shape of a fabric structure .
Keder: Brand name for the solid PVC cord used at a “rope edge”. Rope edges provide
strength and a surface to evenly distribute fabric tension forces.
Lap Seam: Seam created when the two pieces being joined are overlapped by the width
of the seam
Mast: The principal upright in a tension structure.
Warp Yarn: The long straight yarns in the long direction of a piece of a fabric.
Waft Yarns: The shorter yarns of a fabric, which usually run at the right angles to the
wrap yarns.They are also called as filled yarns.

17. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Most commonly observed shapes and forms
Add your text
Mast supported Point supported Arch supported
Frame Supported Simple saddle shaped

18. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Constructional Details
Edge details
Typical Details of connection of members

19. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Constructional Details
Catenery cables at Base Plate to get
Mast, cleats, clips
side connection anchor bolts right
and bale rings
Extruded member with
Tripod head with Membrane Plate
membrane plate
catenery cable the link and connector
and catenery cable

20. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Constructional Details
Edge- curve, cantenary or clamp Tie downs- connector to the ground

21. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Constructional Details-Edge
CONSRTUCTIONAL DETAILS-EDGE
Masts Or Compression Members,Catenary Cables,edge details

22. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Constructional Details-Edge And Center
Bale Rings- Catenary Cables Membrane Plate
Compression Catenery cables are Provide ‘Link’ from embrane to
rings At the top of used along the structural masts.These plates are
conical shaped perimeter stretching installed to accept membrane
structures. from mast to mast Catenery cables and pin connections
Entire structure is installed inside a hardware.
tensiond at the top by pocket inside a
lifting the ring membrane

23. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Issues To Be Considered Before Design Are As Following:
Add your text
1.ECONOMICS:The cost of designing custom components needs to be weighed
against the use of semi-finished products (i.e. tube, pipe, etc.) and fabricated
parts (bolts, nuts, shackles, etc.)
2. MATERIAL :The different material properties (strength, thickness, elasticity, weight, etc.)
make material selection critical.A need for components to be highly abrasion-resistant,
low maintenance and “vandal proof” also influences the choice of suitable materials.
3.PRODUCTION:Various production processes (welding, forging, casting, etc.) have
their own advantages and disadvantages that dictate the design of structural components.
In addition, the quantity of parts required (single vs. mass production), play a significant
role in determining whether a custom component is feasible and cost effective.
4.ANATOMY OF FABRIC: The best way to understand the cost of a fabric structure is
to request a Schedule of Value (SOV) or a breakdown of the major cost (design/engineering/
project management, steel, fabric and hardware fabrication, installation and
equipment and shipping).

24. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Considerations Prior To Design Of TheStructure
Anatomy of a Fabric Structure (% varies)
Plan Area (Length x Width) X Shape Factor (H) =
Surface area
Surface Area X Cost per SQFT= Budget
Design (DD to CD)
Engineering (awning to dome ,Stadium etc)
Project Management (scope of work)
Steel Fabrication (large variable)
Membrane Fabrication (based on complexity)
Installation (location)
Shipping (transport.)
Today’s Materials come in
1. Different widths
2. Variety of colors
3. Some can accept graphics
4. Different light transmission
5.Vary in life span

25. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
BENEFITS OF TEXTILE ARCHITECTURE
Benefits of Textile Architecture
1.Natural Light
Add your text
2.Reverse illumination at Night
3.Easy to handle, as light in weight
4.Unique shapes
5.Retraction, Dismantling & Re-erection
possible
6.Colors available
7.Graphic customization possible
8.Graphic projection possible
9.Rapid on site installation
10.Large clear Spans possible
11.Resistance to corrosive environments
12.Easy to adapt to existing structures for
renovation
13.Can be combined with different materials
14.Can exist in all & extreme climatic
conditions
15.Suitable for a wide spectrum of size &
applications
16.Pre-engineered Modular structures
possible

26. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Benefits of Textile Architecture
BENEFITS OF TEXTILE ARCHITECTURE
Suitaible For Wide Spectrum Of
Resistant To Wide Spectrum Of
Size And Applications
Climatic Conditions
Day And Night Performance Large Clear Spans

27. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
BENEFITS OF TEXTILE ARCHITECTURE
Add your text
Resistance to corrosive
Natural Light Unique Shapes
environment
Easy Combination with other materials Flexible skin Flexible skin

28. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
AVAILIBILITY IN SEVERAL COLOURS

29. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Significance Of Coating
Add your text fabric against weather
1.It seals the
2.provides resistance to ultraviolet light
3.functions as a medium for joining panels
4. fire-rated
Selecting the proper Fabric
1Size
2.Form
3.Span
4.Function
5.Availability
6.Economics
7.Sustainability

30. MEMBRANE’S IN LIGHT WEIGHT AND MEMBRANE
STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Today’s coverings include
Introduction
1.Teflon coated fiberglass (PTFE)
2.Ethylene tetra fluoro ethylene (ETFE)
3.Vinyl coated polyester (PVC/PVDF)
4.High density polyethylene (HDPE)
5. Laminated Products
6.Theatrical Draperies and Stretch fabrics
Polyvinyl Tetra Fluro Ethylene (PTFE)
1.Large scale permanent
structures
2. Non Combustible
3. Life span of over 25
years.
4. Waterproof,resists UV
Rays,chemically inert.
5. Colors now available
membrane bleaches to
milky white

31. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Other “Non-combustibles”…
Add your text
Silicon Coated Fiberglass
•Hybrid PTFE
•TiO2 (Titanium Dioxide) Photocatalyst membrane.

32. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Ethylene Vinyl Coated Polyester
Tetrafluoroethylene (PVC/PVDF)
Add your text
(ETFE) 1.Most cost effective
1.High transparency (97%) 2. Temporary and permanent
2 More than 25 year life span structures.
3. Self cleaning 3. Soft, pliable and easy to handle
4 .Single or multi-layers 4. Less expensive than PTFE
5 100% recyclable. and ETFE
6.Can take 400 times of 5. Variety of colors, weights,
it’s own weight. topcoats and textures.
6. Fire resistant
7. life span of 20+ years

33. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
High Density Polyethylene (HDPE) Tensotherm and GSA Fabrics
1Add your text (UV stable)
Shading only 1.Lightweight,beautifully transluscent.
2 Variety of styles, colors & shade factors 2.Impressive thermal and acoustic benefits.
3 High tensile strength 3.UV protection during the day and
4 Fire and non fire resistant Stunning appearance at night.
5 Well suited for dry/hot climates
6. Protection from sun and hail

34. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Covering mesh and canvas Other Applications
Add your text 1.Textile Facades
Acrylics, Coated and 2.Graphics
Laminates 3. Textures
1.Tent and Awning Industry 4. Digital Printing
2.Variety of styles, colors & 5. Truly unique patterns
patterns
3.Low tensile strength
4.Fire and non fire resistant
5.Exterior Shading Devices

35. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
SEVERAL OTHER USES
Add your text
1.Hides mechanical systems
2.Acoustical helper
3.Light reflector
4.Transforms spaces

36. MEMBRANE’S IN LIGHT WEIGHT AND MEMBRANE
STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
SEVERAL OTHER ALLPLICATIONS
Introduction
Add your text

37. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Add your text
Indore Cricket Stadium Science City Ahmedabad
Nirmal Lifesyle Mumbai
10 Acres City Mall,Ahemadabad Project-Inside Outside Mega show
WESTERN OUTDOORS ,
INDIA
Mahindra World City, Chennai Glenmark Pharmaceutical Ltd.
New Mumbai

38. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
PROJECTS IN INDIA

39. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
REFERENCE:
1.Makowski, Z.S. (1995): Light-weight structures.
2.Gopal Mishra http://theconstructor.org/2009/10/cable-and-tension-structures
3.Ambroziak. A, Klosowski. P .2006.On constructional solutions for
tensile Structures (17-20 ) .
4.Armijos.S, www.fabricarchitect.com (images-20-24)
5.Huntington C. 2004.The tensioned fabric roof . (12-14)
6.Kloiber L,P.E,.Eckmann D, AIA,S.E,P.E,.Meyer.T, Hautzinger .S,2004.
Design consideration in cable stayed roof structure. AI conference,
North American steel construction March 2004, Model steel construction .
7.www.membranes24.com
8.www.architen.com
9.www.taiyomc.com
10.www.tensileworld.com
11.www.FabricArchitect.com

40. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Add your text
THANK YOU
AR.SUVARNA LELE
ER.SHIRISH PATIL

41. ‘MEMBRANE’S’IN
LIGHTWEIGHT AND
MEMBRANE STRUCTURES
AR.SUVARNA LELE
ER.SHIREESH PATIL
CHAUGULE PATIL CONSULTANTS P
LTD
Guimarães, Portugal – 21-23 July 2010

42. MEMBRANE’S IN LIGHT WEIGHT AND
MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Introduction
Tensile structures
They are Light weight as their structural stability is derived from their pre
stressed shape rather than the mass of material used .
Tensile structures allow larger spans with easier and cheaper constructions
and they cover vast expanse of spaces.
Membranes are uniform in thickness with a capacity to support imposed
loads due to their designed shapes and deflections.

43. MEMBRANE’S IN LIGHT WEIGHT AND
MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
The aim of this paper is to take an overview of the ‘Membranes’ in cable
and membrane structures.
Before installation on site a membrane has to go through several stages
right from design including the steps as form finding, load analysis and
design of fabric geometry.
The paper also talks about several shapes and forms a membrane can
achieve and the principle behind the design of these shapes.
Important aspect of membrane structure is availability of membranes in
market. This paper accounts various available covering materials in the
market and the criteria have to be considered before their installations on
the site.

44. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
BASIC SHAPES AND FORMS
Synclastic surface .( fig 1) Anticlastic surface .(fig 2)
Membrane structure depends on double curvature to resist the imposed loads. The
shapes can be deciding factor of resistance of loads. The surfaces can be categories
in Synclasic and Anticlasic surfaces.
1]Synclastic surface: Upward loads are resisted by a stress increase about both axes
of the fabric while downward loads are neutralized by internal pressure. Inflatable
fabric structures are simplistic forms.( fig 1)
2]Anticlastic surface: Fibers with convex curvature. One surface resists the upward
load by increasing tension, while fibers with concave surface increase their tension to
resist downward loads.(fig 2)

45. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
BASIC SHAPES AND FORMS
The basic forms of all curvatures are hyperbolic paraboloids, cones or arches
Hperbolic
Paraboloid Cone Arch
thread in tension changes conventional materials Curvature provides
geometry when in in tension and resistance to out of
Compression. compression. plane forces.
Tension conditions between tensile and conventional materials

46. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Evolution Of Several Forms From The Basic
Add your text
6 point membrane Chinese hat Center arch
Rectangular pneu 3D node Custom2
Custom1
Rhino design
Some More Shapes
(www.membranes24.com)

47. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Add your text
Inflated bubble
Some More Shapes

48. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
DESIGN PROCESS
1.The first step in designing a fabric structure is to create a form with sufficient
PRE-STRESS or tension. Fabric structures must be clamped to a frame or be
pre-stressed in order to avoid “fluttering” like a flag or sail.
2.The second step is to DETERMINE THE BOUNDRIES of the tensioned fabric.
Boundaries include frames, walls, beams, columns and cables. The fabric is either
continuously clamped to frames, walls or beams or attached to columns with membrane
plates with adjustable hardware. In most cases the fabric forms a curved edge or
“CATENERY” between connection points requiring a cable, webbing belt or rope to
carry loads to the major structural points.
3.Once the primary points have been determined, the third step is referred to as
“FORM FINDING”. Form finding is the art of discovering the most efficient structure
which can be fabricated with as little waste as possible and can be transported and
installed with ease, installation and fabrication.
4.The last step in the design process is ANALYSING the structure’s response to
loads, including dead loads and live loads (snow, wind, etc.).

49. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE,
ER SHIRISH PATIL
Flowchart :Illustrating
General Approach to Tensile
Membrane Structure Design
and Engineering
Add your text

50. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Tensile membranes design process, from conception to realization
Add your text
Architects
Requirements
Conception
Construction,elevation
Form Finding
Membrane cutting and
manufacturing
Analysis
Cutting pattern
Detailing generation
Engineers
Contractors,Manufacturers.

51. MEMBRANE’S IN LIGHT WEIGHT AND
MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Hybrid Method Proposed for Tensile Membrane Design
Grid Generation Form Finding Surface Fitting Render
(a) Grid Generation, (b) Form finding (c) Surface fitting, (d)Render
representation
Representation of a membrane structure with a nodal force using a 5x5 grid

52. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
FROM CONCEPT TO SITE
1.SKETCHING.
2.COMPUTER DRAWING
3.PHYSICAL MODELLING
4.ACTUAL SITE
INSTALLATION
http://fabricarchitecturemag.com/articles/0708_rv2_rhino.html

53. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Form-finding
1.Soap and liquid plastic films: soap and liquids are excellent mediums to
experiment with as they exhibit excellent tensile capacity but lack shear
capacity. Wire or strings can act as cables and liquid as well as soap films
will form anticlastic shapes of pre stressed structures. The film or bubble
can be stretched to the limits till it breaks. Various shapes which are
formed after stressing the film can be noted and applied for further design.
2.Physical models Building:plays a significant part in design of structure.
The limitations and possibilities can be worked out by experimenting on
the physical models. The miniature model must carry or be identical with
the actual structure in properties. The structures are to be designed to be
in equilibrium conditions for applied loading conditions. The structures
mostly are designed to carry uniform pre stress in their membranes
Experimenting on physical models for evolution of different forms

54. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Add your text
Actual cutting process

55. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
TECHNICAL TERMS IN DESIGN OF TENSILE STRUCTURES
Base Fabric: The uncoated fabric, also known as greige goods.
Bias: Oriented at 45 degrees to the warp and fill directions of the fabric.
Add your text
Biaxial: Taken along two concurrent orthogonal directions, usually principal
directions.
Butt Seam: Seam created when the two pieces of fabric being joined together
are butted together with a strip twice the width of the seam.
Catenary Cable Pocket: Edge treatment in which the fabric is folded over
on itself to form a pocket in which a catenary cable can be installed.
Catenary Cable Fitting: Device attached to the end of a cable to allow a
connection to another member. Fittings are swaged.
Catenary: The curve theoretically formed by a perfectly flexible, uniformly dense fabric.
Catenary Cable Fitting: Steel cables that run through the pockets on the
perimeter of a tension fabric structure. The shape of the cable follows
that of the pocket, which is typically curved with a ratio of 1:10.
The length of the cable is determined by the project engineer supplying
the fabric patterning. The thickness of the cable is determined by the
engineer who calculates the reaction loads at the cable ends.
Coating: A material applied to a fabric for waterproofing and protection of
the fabric yarns.
Coating Adhesion: Strength of the bond between the substrate of a fabric
and the coating.

56. MEMBRANE’S IN LIGHT WEIGHT
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TECHNICAL TERMS
Compensation: The operation of shop fabricating a fabric structure of pieces
of the structure smaller in the unstressed condition than the actual installed size, to
Add your text the stretch at pre-stress level.
account for
Elongation: The change in lengths of a material sample; normally this is
associated with some load or force acting on the sample. In fabric, this elongation. does
not normally refer to true strain of the fiber elements as in the classical sense; but,
rather, normally refers to the apparent” strain resulting from a straightening out of the
crimped yarns in the fabric matrix.
Equilibrium Shape: The configuration that a tensioned fabric surface assumes when
boundary conditions, pre-stress level, and pre-stress distribution are defined.
Fabric Clamp: Device for clamping the edge of a fabric panel, usually a bar or channel
shape and made of aluminum or steel.
Form Finding: The process of determining the equilibrium shape of a fabric structure .
Keder: Brand name for the solid PVC cord used at a “rope edge”. Rope edges provide
strength and a surface to evenly distribute fabric tension forces.
Lap Seam: Seam created when the two pieces being joined are overlapped by the width
of the seam
Mast: The principal upright in a tension structure.
Warp Yarn: The long straight yarns in the long direction of a piece of a fabric.
Waft Yarns: The shorter yarns of a fabric, which usually run at the right angles to the
wrap yarns.They are also called as filled yarns.

57. MEMBRANE’S IN LIGHT WEIGHT
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Most commonly observed shapes and forms
Add your text
Mast supported Point supported Arch supported
Frame Supported Simple saddle shaped

58. MEMBRANE’S IN LIGHT WEIGHT
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AR.SUVARNA LELE ER.SHIRISH PATIL
Constructional Details
Edge details
Typical Details of connection of members

59. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Constructional Details
Catenery cables at Base Plate to get
Mast, cleats, clips
side connection anchor bolts right
and bale rings
Extruded member with
Tripod head with Membrane Plate
membrane plate
catenery cable the link and connector
and catenery cable

60. MEMBRANE’S IN LIGHT WEIGHT
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AR.SUVARNA LELE ER.SHIRISH PATIL
Constructional Details
Edge- curve, cantenary or clamp Tie downs- connector to the ground

61. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Constructional Details-Edge
CONSRTUCTIONAL DETAILS-EDGE
Masts Or Compression Members,Catenary Cables,edge details

62. MEMBRANE’S IN LIGHT WEIGHT
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AR.SUVARNA LELE ER.SHIRISH PATIL
Constructional Details-Edge And Center
Bale Rings- Catenary Cables Membrane Plate
Compression Catenery cables are Provide ‘Link’ from embrane to
rings At the top of used along the structural masts.These plates are
conical shaped perimeter stretching installed to accept membrane
structures. from mast to mast Catenery cables and pin connections
Entire structure is installed inside a hardware.
tensiond at the top by pocket inside a
lifting the ring membrane

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Issues To Be Considered Before Design Are As Following:
Add your text
1.ECONOMICS:The cost of designing custom components needs to be weighed
against the use of semi-finished products (i.e. tube, pipe, etc.) and fabricated
parts (bolts, nuts, shackles, etc.)
2. MATERIAL :The different material properties (strength, thickness, elasticity, weight, etc.)
make material selection critical.A need for components to be highly abrasion-resistant,
low maintenance and “vandal proof” also influences the choice of suitable materials.
3.PRODUCTION:Various production processes (welding, forging, casting, etc.) have
their own advantages and disadvantages that dictate the design of structural components.
In addition, the quantity of parts required (single vs. mass production), play a significant
role in determining whether a custom component is feasible and cost effective.
4.ANATOMY OF FABRIC: The best way to understand the cost of a fabric structure is
to request a Schedule of Value (SOV) or a breakdown of the major cost (design/engineering/
project management, steel, fabric and hardware fabrication, installation and
equipment and shipping).

64. MEMBRANE’S IN LIGHT WEIGHT
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Considerations Prior To Design Of TheStructure
Anatomy of a Fabric Structure (% varies)
Plan Area (Length x Width) X Shape Factor (H) =
Surface area
Surface Area X Cost per SQFT= Budget
Design (DD to CD)
Engineering (awning to dome ,Stadium etc)
Project Management (scope of work)
Steel Fabrication (large variable)
Membrane Fabrication (based on complexity)
Installation (location)
Shipping (transport.)
Today’s Materials come in
1. Different widths
2. Variety of colors
3. Some can accept graphics
4. Different light transmission
5.Vary in life span

65. MEMBRANE’S IN LIGHT WEIGHT
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BENEFITS OF TEXTILE ARCHITECTURE
Benefits of Textile Architecture
1.Natural Light
Add your text
2.Reverse illumination at Night
3.Easy to handle, as light in weight
4.Unique shapes
5.Retraction, Dismantling & Re-erection
possible
6.Colors available
7.Graphic customization possible
8.Graphic projection possible
9.Rapid on site installation
10.Large clear Spans possible
11.Resistance to corrosive environments
12.Easy to adapt to existing structures for
renovation
13.Can be combined with different materials
14.Can exist in all & extreme climatic
conditions
15.Suitable for a wide spectrum of size &
applications
16.Pre-engineered Modular structures
possible

66. MEMBRANE’S IN LIGHT WEIGHT
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Benefits of Textile Architecture
BENEFITS OF TEXTILE ARCHITECTURE
Suitaible For Wide Spectrum Of
Resistant To Wide Spectrum Of
Size And Applications
Climatic Conditions
Day And Night Performance Large Clear Spans

67. MEMBRANE’S IN LIGHT WEIGHT
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BENEFITS OF TEXTILE ARCHITECTURE
Add your text
Resistance to corrosive
Natural Light Unique Shapes
environment
Easy Combination with other materials Flexible skin Flexible skin

68. MEMBRANE’S IN LIGHT WEIGHT
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AVAILIBILITY IN SEVERAL COLOURS

69. MEMBRANE’S IN LIGHT WEIGHT
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Significance Of Coating
Add your text fabric against weather
1.It seals the
2.provides resistance to ultraviolet light
3.functions as a medium for joining panels
4. fire-rated
Selecting the proper Fabric
1Size
2.Form
3.Span
4.Function
5.Availability
6.Economics
7.Sustainability

70. MEMBRANE’S IN LIGHT WEIGHT AND MEMBRANE
STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
Today’s coverings include
Introduction
1.Teflon coated fiberglass (PTFE)
2.Ethylene tetra fluoro ethylene (ETFE)
3.Vinyl coated polyester (PVC/PVDF)
4.High density polyethylene (HDPE)
5. Laminated Products
6.Theatrical Draperies and Stretch fabrics
Polyvinyl Tetra Fluro Ethylene (PTFE)
1.Large scale permanent
structures
2. Non Combustible
3. Life span of over 25
years.
4. Waterproof,resists UV
Rays,chemically inert.
5. Colors now available
membrane bleaches to
milky white

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Other “Non-combustibles”…
Add your text
Silicon Coated Fiberglass
•Hybrid PTFE
•TiO2 (Titanium Dioxide) Photocatalyst membrane.

72. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
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Ethylene Vinyl Coated Polyester
Tetrafluoroethylene (PVC/PVDF)
Add your text
(ETFE) 1.Most cost effective
1.High transparency (97%) 2. Temporary and permanent
2 More than 25 year life span structures.
3. Self cleaning 3. Soft, pliable and easy to handle
4 .Single or multi-layers 4. Less expensive than PTFE
5 100% recyclable. and ETFE
6.Can take 400 times of 5. Variety of colors, weights,
it’s own weight. topcoats and textures.
6. Fire resistant
7. life span of 20+ years

73. MEMBRANE’S IN LIGHT WEIGHT
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AR.SUVARNA LELE ER.SHIRISH PATIL
High Density Polyethylene (HDPE) Tensotherm and GSA Fabrics
1Add your text (UV stable)
Shading only 1.Lightweight,beautifully transluscent.
2 Variety of styles, colors & shade factors 2.Impressive thermal and acoustic benefits.
3 High tensile strength 3.UV protection during the day and
4 Fire and non fire resistant Stunning appearance at night.
5 Well suited for dry/hot climates
6. Protection from sun and hail

74. MEMBRANE’S IN LIGHT WEIGHT
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AR.SUVARNA LELE ER.SHIRISH PATIL
Covering mesh and canvas Other Applications
Add your text 1.Textile Facades
Acrylics, Coated and 2.Graphics
Laminates 3. Textures
1.Tent and Awning Industry 4. Digital Printing
2.Variety of styles, colors & 5. Truly unique patterns
patterns
3.Low tensile strength
4.Fire and non fire resistant
5.Exterior Shading Devices

75. MEMBRANE’S IN LIGHT WEIGHT
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SEVERAL OTHER USES
Add your text
1.Hides mechanical systems
2.Acoustical helper
3.Light reflector
4.Transforms spaces

76. MEMBRANE’S IN LIGHT WEIGHT AND MEMBRANE
STRUCTURES
AR.SUVARNA LELE ER.SHIRISH PATIL
SEVERAL OTHER ALLPLICATIONS
Introduction
Add your text

77. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
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Add your text
Indore Cricket Stadium Science City Ahmedabad
Nirmal Lifesyle Mumbai
10 Acres City Mall,Ahemadabad Project-Inside Outside Mega show
WESTERN OUTDOORS ,
INDIA
Mahindra World City, Chennai Glenmark Pharmaceutical Ltd.
New Mumbai

78. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
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PROJECTS IN INDIA

79. MEMBRANE’S IN LIGHT WEIGHT
AND MEMBRANE STRUCTURES
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REFERENCE:
1.Makowski, Z.S. (1995): Light-weight structures.
2.Gopal Mishra http://theconstructor.org/2009/10/cable-and-tension-structures
3.Ambroziak. A, Klosowski. P .2006.On constructional solutions for
tensile Structures (17-20 ) .
4.Armijos.S, www.fabricarchitect.com (images-20-24)
5.Huntington C. 2004.The tensioned fabric roof . (12-14)
6.Kloiber L,P.E,.Eckmann D, AIA,S.E,P.E,.Meyer.T, Hautzinger .S,2004.
Design consideration in cable stayed roof structure. AI conference,
North American steel construction March 2004, Model steel construction .
7.www.membranes24.com
8.www.architen.com
9.www.taiyomc.com
10.www.tensileworld.com
11.www.FabricArchitect.com

80. MEMBRANE’S IN LIGHT WEIGHT
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THANK YOU
AR.SUVARNA LELE
ER.SHIRISH PATIL