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case study and basic information about tensile structures

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TENSILE STRUCTURES

TENSILE STRUCTURES-7

Architects are constantly looking for new methods to create large indoor spaces without providing columns and supports. Tensile and cable strut structures are one method of producing such spaces. They also enable the creation of different shaped spaces allowing architects more scope for innovation.free-standing Tension structures From tensegrity systems to cable-strut System provides the background engineering needed to produce these wonderful structures.NEED OF STUDY- Today looking at the current scenario there is a need to go ahead with tensile structures rather than typical building structures. As there are many purposes, which can be dealt with a tensile structure thereby, reducing the need to construct built forms They provide elegant, energy efficient and economical solutions where large open spans are required. Tensile structures are very cheap alternative to traditional construction when tried to cover large areas. Tensile have primary advantage of not being subject to buckling failure. They do not depend on the stiffness of the material but their tensile strength.

AIM and OBJECTIVES-1. To document the study of the tensile fabric structure, their history and how they develop during all these years.2. To study the need of tensile structures according to the changing time.3. To study the basic support system and document visual and written material available from the case studies.

LITERATURE REVIEW-This research paper will talk about the properties, energy and cost efficiency, support systems and workability of tensile structures. About how tensile structures are installed and maintained, and what materials and phenomenon is required to achieve great strength.

METHODOLOGY-1. Identify the topics relevant to the study on which information is to be sought.2. Extracting data from the topics found out.3. Collecting the data related to the history of tensile structures, technology, types, support system etc.4. Verifying and analyzing the data and jotting down the relevant part of it in points.5. Identifying the positive and negative points of tensile structure.6. Understanding the need of tensile structure.

HYSTORY OF TENSILE ARCHITECTURE-Most buildings today are basically compression structures. Walls are formed by piling up blocks and bricks on one another, or else wood or metal are used to create forms for rigid materials to hang from or sit on top of it. There is another way to build, though, using flexible materials and the force of tensions, rather than weight, to hold things together. Although tensile Architecture is a fancy modern name for it, and this is probably the oldest and simplest method human beings have devised to provide shelter. The earliest examples of tensile structures were tents built by the nomadic tribes. Their forms were distinct and evolved in response to climatic conditions, materials available and structural principles used. For instance tribe build a cold northern region of Europe, Asia and North America had a conical framework of inclined poles arranged in circle that are secured at the top and covered with animal skins.

MODERN TENSILE ARCHITECTURE- The last thirty years has been a rapid progress from tents to membrane structures and it was in the world exposition 1970 that membrane structures and it was in the world exposition 1970 that membranes were commercially introduced. The main credit for the expensive architectural study and development of tensile structures goes to Frio Otto and his light weight structures research institute at Stuttgart University, Germany. He was the first to lead away from the simple geometric solutions to the organic free forms that could respond to complex planning and structural requirements. The secret of Ottos success lies in his study of the self-forming processes of soap bubbles, crystals, microscopic plants, animal life, and branching system. He found that natural objects will create forms that are very efficient, wasting nothing and use a minimum of material. Tensile structures are one of the most promising trends in contemporary architecture. Frei Otto began building cotton fabric canopies using tent technology. Otto realized that structural and architectural forms are inseparable.

NEED OF TENSILE STRUCTURES;NO FOUNDATIONS- All the tensile structures can be installed with no foundation. Anchoring is accomplished in different manners for different surfaces.NO PERMITS- No foundation is very important consideration because of the reduced installation costs, time needed for installation and because over the years we have found many times NO FOUNDATION means NO PERMIT.QUICK ASSEMBLY- Both fabric shelters and fabric structures can be erected faster than virtually any other type of structure in the market. Smaller sizes can be erected by a crew of two or three people using hand tools and a couple of ladders in as little as few hours in a day or two. Larger sizes may require lifting equipment, a three to five person crew and a few days. As a rule of thumb; large fabric-structures can be erected at the rate of about 2000 square feet per day with the crew of four to five people. Because of their lightweight and ease of assembly; these temporary structures are perfect for use as instant workshops in remote locations and on construction sites. Because there is no expensive foundation required you are able to erect a fabric shelter or fabric-structure in less time, with less efforts and less hassles than any other product in the market.PERMANENT- Large fabric structures are built for long term use, 15 to 25 years or more, our clear span designs have been in use for over a quarter century. We may not realize the importance of this significance unless we realize our smallest fabric-shelters use the exact same kinds of quality materials as some of the largest structures. Once we realize this we will understand why users still find themselves using their temporary solutions for protections in the same place even after 5, 10, 20 years.PORTABLE- All fabric structure and fabric shelters can be unassembled in about half of the time that is required to assemble them; which makes relocated shelter or structure simple to achieve. When a job or application is completed the shelter or structure can be moved to the new location where it can be used again. If you no longer have the need for the unit you easily resell it.FUNCTIONALITY- Compared to classic architecture, textile architecture involves the use of a smaller amount of materials, an undisputed advantage for large projects. Translucent fabric creates a bright and convivial environment, the daylight bringing a smooth and natural interior lighting.ASTHETICS- Textile architecture means a huge scope of creative and attractive designs. At night, translucent fabrics and interior light emphasize building design.OPEN AND CLOSED SYSTEMS- The pretention is transmitted to a support system, which can be either closed or open or a mixture of the two. An open system is best defined by having a cable around the perimeter of the fabric; this transmits the load to the support system. These loads can be massive and require large concrete tie down blocks. A closed system is defined by having the rigid members around the edge. These are designed to counter the pretention put upon the fabric more like a conventional blocking. Closed system structures require smaller foundations.CLEAR-SPAN- All standard fabric shelters and fabric structures are clear span; means you get more cubic feet of coverage than virtually any other type of construction. This extremely important when interior height is a concern because you get more usable space than with the standard construction methods. There are no internal poles of supports of any kinds to get in your way or to have to work around.NATURAL LIGHT- Practically when visited any of tensile fabric structure we dont need specific provision for artificial lighting. The feeling you get inside one of the tensile structure or shelter gives you an open airy feeling of being outdoors. When you choose a translucent fabric there is normally enough light transmittance that artificial lights are not required in day light hours to more most of the tasks. If you require an environment that demands dark you can choose an opaque or blackout fabric. These fabrics will not allow light to transmit through and will create a totally dark environment.

ADVANTAGES- Unique building material. Lightweight and flexible, fabric interacts with and expresses natural forces. Tensile fabric structures are an environmentally sensitive medium. Tension is the most efficient way of using any material, it utilizes the materials at its extreme of the cross sectional forms as in bending and compression loads. Fabric structure have higher strength/weight ratio than concrete or steel. Most fabrics can be recycled. A fabric structure can be designed for almost any condition, heavier fabrics and three dimensional forms will cope with extreme wind and snow loads.DISADVANTAGES- Fabric structures being mainly fabric and cables have little or no rigidity and therefore must rely on their forms and internal pre-stressed to perform this function. As a thumb rule, span greater than 15 meters should be avoided however, much greater spans can be achieved by reinforcing the fabric with webbing and cables. Loss of tension is dangerous for the stability of the structure and if not regularly maintained will lead to failure of the structure. If an open system structure is to about a building then care needs to be taken with loadings. Trying to successfully control water from an open system structure is difficult and requires guttering.

BRIDGES:For 4,000 years tensile principles have been used in bridge building as the only way to span large distances. Throughout the Far East and South America, suspension bridges made of sop and bamboo were used. Although bamboo is quite strong, it is not very durable. A more lasting solution came in 100AD, when the Chinese invented wrought iron.Some of the early bamboo bridges could span over 800 feet. It was not until the introduction of steel cable in the nineteenth century that western engineering could greatly increase span. The inventor of steel cable was John Roebling who designed a number of suspension bridges in the United States. His masterpiece, the Brooklyn Bridge still remains one of the finest bridges ever built.

The Nature of Tensile Fabric StructureIntroduction:Fabric is unique as an architectural tool, the sculptural forms that can be achieved are offered by no other medium; however certain simple rules must be obeyed.What is tension?Tension is the force used to pull the molecular structure if a material apart. It is the most efficient way of using any material because it utilizes the whole cross section at maximum efficiency rather than just the material at the extremes of the cross sectional form, as in bending and compression loads. Take the example of a stick; it will break under compression or bending loads, long before it would be pulled apart by tension. Tension loads maximize the load capacity of materials, or to put it another way, requires the least material.What is a tensioned fabric structure?True tensile fabric structures are those in which every part of the fabric is in tension. The fundamental rule for stability is that a tensioned fabric structure must curve equally in opposite directions, this gives the canopy stability. This is known as an anti classic form and mathematically as a hyperbolic paraboloid.Common Misconceptions:It is commonly believed that fabric structures cannot cope in heavy weather conditions .This is untrue. A fabric structure is designed for almost any conditions, heavier fabrics and more 3 dimensional forms will cope with, for example, extreme wind and snow loads, we ourselves have built structures in typhoon and tornado zones.It is commonly believed that the fabric is stretchy or elastic in nature; again this is untrue. If the fabric were elastic, it would balloon under wind loads and settle under snow. A typical structural external fabric has a tensile strength of 10 tons per linear meter and will creep no more than a few percent after 20 years of extreme conditions. The fabric is alive and does creep, which we take into consideration during the engineering, but basically fabric needs to be thought about as being totally inert in the initial stages. The complex 3 dimensional form of a canopy is achieved not by elasticity but by a cutting pattern where strips of material, between 1m and 2m wide, with non-parallel sides are sewn or welded together.What is tension in the fabric of a fabric tensile structure? We put the fabric of a tensile structure under tension. We do not stretch the fabric into position. It is cut and bonded together to make its final shape. We will load the fabric during erection. This loading or tension which we have pre-engineered is called pre-tension or pre-stress.Pre-tension is the most efficient way of resisting live loads snow, wind etc.A person can happily walk over a tensile fabric structure once tensioned, the fabric is extraordinary tight. If you throw a brick on the fabric it will simply bounce off. These imposed loads or live loads are therefore appropriate when the designer wishes to use the minimum amount of material for either functional or aesthetic reasons.Open and Closed Systems:The pre-tension is transmitted to a support system, which can be either closed or open or a mixture of both. An open system is best defined by having a cable around the perimeter of the fabric; this transmits the load to the support system. These loads can be massive and acquire large concrete tie down blocks. A closed system is best defined by having rigid members around the edge. These are designed to counter the pre-tension put upon the fabric more like a conventional building. Closed system structures require smaller foundations. Both systems open and closed can be combined which is particularly useful if one is trying to abut to a building and gain weather protect.What is a tensioned fabric structure?True tensile fabric structures are those in which each part of the fabric is in tension. A tensioned fabric structure mesh curve equally in opposite (vertical) directions, this gives the canopy 3 dimensional stability. This is an anticlastic form and seen most simply as a hyperbolic paraboloid. A proportion of 4:1 between horizontal span and vertical articulation is desirable. The more irregular and the flatter the form is, the more we need to load the material to stabilise the shape .The fabric is loaded during erection, called pre-tension or pre-stress.Fabric is inelastic in nature. If the fabric were elastic, it would distort under wind and snow loads .A typical external fabric has a tensile strength of 10 tonnes per linear metre and will creep a few percent after 20 years. Fabric needs to be thought of as being totally inert. The complex 3 dimensional form of a canopy is achieved not by elastic fabric but by a cutting pattern where strips of material with non-parallel sides are sewn or welded together.

Concept:Testing Initial Concepts for Viability:True tensile fabric structures must have double curvature designed into the fabric. These curves work in opposite directions to each other to resist imposed loads (outside forces), giving 3 dimensional stability. This mathematically is called a hyperbolic parabolic and is the anticlastic form. The low points resist uplift and the high points resist downloads. The easiest way to understand this is by using a soap bubble model. I do not suppose that there is anyone in this room who has not occasionally blown a common soap-bubble, and while admiring the perfection of its form, and the marvellous brilliancy of its colours, wondered how such an object can be so easily produced.I hope that none of you are yet tired of playing with bubbles, because, as I hope we shall see, there is more in a common bubble than is first apparent.

Soap-bubble Demonstration:Taking a basic wire frame in the shape of a hyperbolic parabolic we dip this into soapy water, pulling the frame out you will see a soapy film suspended within the frame. This saddle-like elastic skin of liquid represents our fabric with its anticlastic form. This skin is the minimum surface area of that frame, due to the surface tension of the liquid .It has the least surface area that can web within the frame .The more irregular and the flatter the fabric is, the more we need to load the material to stabilize the shape . The fabric should have sufficient curvature in both directions preferably roughly similar but at the same time not too extreme. A proportion of 4:1 between horizontal span and vertical articulation is desirable.A contractors experience regarding the most efficient form should be sought at an early stage, particularly if cost is an issue. However, by doing this exercise with a soap bubble model you can see the stresses in the skin by its colour change.

Making a Model Demonstration:At this early stage making a stocking model from a pair of stockings of Lycra material is very helpful to visualise what can now be quite a complex three dimensional form. I find that using a cardboard box with one side cut out and pinning the fabric out is very helpful. By inserting objects, such as a pencil beneath the fabric and deforming it upwards you can start to appreciate what the fabric could look like (without the use of Superglue).With our box being our required coverage and our pencils being our internal support structure we can consider spans. Large dynamic sweeps of fabric have to be supported and have to resist the worst case of uplift and down loads from snow, wind etc.

CASE STUDY 1: PEDESTRIAN OVER BRIDGE IN KOTHRUD

1. Pedestrian over bridge, kothrud.INTRODUCTION:This pedestrian bridge was built in 2009 mainly for elderly people to be able to cross the high traffic Karve road. Unlike other pedestrian bridges in Pune this bridge is comparatively a new structure made by using tensile property of materials (tensile structure).This structure consists of mail steel members i.e. struts supported on steel beams which are resting on R.C.C end columns. Tensile fabric is used as roofing material.

2.1 Connections between fabric roofing and steel 2.2 struts.

3. Connection between fabric roofing and central spinal beam.

3.PVC coated fabric roofing stretched by high tensile steel wires to induce tension forming hyperbolic parabolide form (two way curve).CASE STUDY 2- CHATRAPATI SHIVAJI AIRPORT, MUMBAI, ARRIVALS CANOPY

INTRODUCTION-Created on- 11 may 2010Total area- 4461 sq.mFabric- PVC

Function of this project was to cover the arrival platform of Mumbai Airport (International terminal adding welcoming and unique atmosphere for international visitors. Architectural membrane canopy to cover the arrivals platform of Mumbai Airport in India. The architect wanted modular based structures offering visual impact, shade and protection from Mumbai's extreme weather. Mumbai Arrivals Canopy was created using only a mild steel frame, PVC membrane, and galvanized high strength cables. Structure designed as a linked ST120 (modular type structure) inverted conical membrane. Structural columns are used as a downpipe connected to underground services. Provision for rain water collection during Mumbai's monsoon season was of significant importance. Provision for rain water collection during Mumbai's monsoon season was of significant importance.

Arrivals canopy- inverted conical shape which helps in collecting rain water which is a silent feature of this canopy

Connection between high tensile steel cables and roofing material.

Decorative hollow pipes for End connection of steel cables and collecting rain-water roofing material

AIR SUPPORTED STRUCTURE:An air supported structure is any structure that derives its structural integrity from the use of internal pressurized air to inflate a pliable material(i.e. structural fabric)envelope, so that air is the main support of the structure. It is usually dome-shaped, since this shape creates the strongest structure for the least amount of material. To maintain structural integrity, the structure must be pressurized such that the internal pressure is equal to or exceeds any external pressure being applied to the structure (i.e. wind pressure).The structure doesnt have to be airtight to retain structural integrity. As long as the pressurization system that supplies internal pressure replaces any air leakage, the structure will remain stable. All access to the structure interior must be equipped with 2 sets of doors or revolving door (airlock).Air-supported structures are secured by heavy weights on the ground, ground anchors, attached to a foundation, or a combination of these.Among its many uses are: sports and recreation facilities, warehousing, temporary shelters. The structure can be either wholly, partial, or roof-only air supported. A fully air-supported structure can be intended to be a temporary or semi temporary facility or permanent, whereas roof-only air supported structures can be built as permanent buildings.

DESIGN: SHAPE:The shape of an air-supported structure is limited by the need to have the whole envelope surface evenly pressurized. If this is not the case, the structure will be unevenly supported, creating, creating wrinkles and stress points in the pliable envelope which in turn may cause it to fail.In practise, any inflated surface involves a double curvature. Therefore the most common shapes for air-supported structures are hemispheres, ovals, and half cylinders.STRUCTURE:The main loads acting on the air-supported envelope are the internal air pressure, wind and snow loads. In order to cope with the varying loads of wind and snow, the inflation of the structure must be adjusted accordingly .Modern structures have computer controlled mechanical systems that can sense the dynamic loads and compensate the inflation for it. The highest quality ones are those that withstand winds up to 120mph (190kmph) and snow loads up to 40 lbs.Of course, the air pressure on the envelope is equal to the air pressure exerted on the inside ground, pushing the whole structure up. Therefore it needs to be securely anchored to the ground for substructure in the case of roof-only .For wide span structures; cables are required for anchoring and stabilization. All forms of anchoring require some form of ballast. Earlier designs used to use sand bags, concrete blocks, bricks, or the like; placed all around the perimeter on the skirt .Nowadays most manufacturers have proprietary anchoring systems.Danger of sudden collapse is nearly negligible, since the structure will deform or sag in case a heavy load (snow or wind) is exerted on it. Only if these warning signs are ignored, then the build-up of an extreme load may rupture the envelope, leading to a sudden deflation and collapse.MATERIAL:The materials used for air-supported structures are similar to those used in tensile structures, namely synthetic fabrics such as fibreglass and polyester. In order to prevent deterioration form moisture and UV radiation, these materials are coated with vinyl such as PVC and Teflon.Depending on use and location, the structure may have inner linings made of lighter materials for Insulation and acoustics.AIR PRESSURE:The interior air pressure required for air supported structures is not as much as most people expect and certainly not discernible when inside. The amount of pressure required is a function of weight of the material-and the building systems suspended on it(lighting, ventilation etc) and wind pressure. Yet it only amounts to a small fraction of atmospheric pressure.

ADVANTAGES AND DISADVANTAGES:BC Place Stadium with its large air-supported roof.There are some advantages and disadvantages as compared to conventional buildings of similar size and application.ADVANTAGES: -Considerably lower initial cost than conventional buildings.-lower operating costs due to simplicity of design (wholly air-supported structures only)-Easy and quick to set up, dismantle, and relocate (wholly air-supported structures only)-Unobstructed open interior space, since there is no need for columns-Able to cover almost any project.-custom fabric colours and sizes, including translucent fabric, allowing natural sunlight in DISADVANTAGES:-Continuous operation of fans to maintain pressure, often requiring redundancy or emergency power supply.-Dome collapses when pressure is lost or fabric compromised.-Cannot reach the insulation values of hard walled structures, increasing heating, cooling costs.-Limited load carrying capacity.-Conventional buildings have longer lifespan.

APPLICATIONS OF MEMBRANE BUILDINGS:The applications of membrane buildings are highly diverse.The focus of textile building is on the following areas: PUBLIC EVENT BUILDING:Temporary or permanent roofings and also enclosed buildings form attractive experience oriented spaces for exhibitions, shows, concerts, sports events etc.TOURISM AND CATERING:Due to their lightness and expanse, textile buildings provide an attractive accent as a protection against sun, wind and rain.PARK AND LANDSCAPE SPACES: Protected spaces for visitors should meaningfully fit the natural environment.OPEN AIR THEATRES:Frequently, open air theatres suffer from their weather dependency. In particular, movable roofings permit maintenance of the specific and attractive character of open-air theatres, yet also provide weather protection, if needed.LEISURE PROPERTIES:Airy, imaginative designs offer an attractive alternative, particularly in the field of leisure and adventure parks.SPORTS BUILDINGS:In addition to the protection against the influence of weather, textile roofings convince above all by interesting forms and the open-air character which is maintained by the high light transparency of the membrane.ENTRANCE AND WALKWAY AREAS:Weather protection by eye catching and spectacular membrane designs also in this field increasingly convinces building owners and planners.SHOPPING MALLS AND EXHIBITION SPACES:Exceptional membrane architecture supports marketing concepts which make shopping experience-oriented shopping.RAILWAY STATIONS, AIRPORTS ETC:For the area of public buildings for transportation and traffic, unconventional membrane buildings offer an ideal symbiosis of function and aesthetics.SKYLAR:Sculptural shade feature, multiple unit layouts available. Ideal for gardens, leisure and retail locations.IRON MOUNTAIN:Prominent free-standing entrance canopy to about buildings with an optional weather seal, or extend over single-storey roof.MISTRAL:Elegant hyper canopy creates focal point for public spaces, school play areas.MALVERN VAULT:Modular walkway unit and stand alone structure. Seating shelter, link between buildings, play area shade.SAVANNA:Modular structure to which additional units can be added. Temporary event canopy or permanent structure, providing external teaching areas, multi-use public space.

BASIC SUPPORT SYSTEM IDEAS:-Conventional structures have an internal rigidity to the stable.-Fabric structures being mainly fabric and cables have little or no rigidity and therefore must rely on their form and internal pre-stress to perform the same function.-To resist these loads we have to put equal loads into the fabric for it to remain stable, the pre-stress.-Because fabric structures rely on internal tensile forces to remain stable their behaviour is more complicated than their conventional counterparts and therefore they are more difficult to design.-The significant changes in their geometry means they are non-linear even though the fabric remains more or less stable.-If properly designed this is a desirable quality that increases their ability to carry load as they deform from the effect of live loads.-Fabric structures are more capable in this respect due to their very high strength weight ratio than equal spans of concrete or steel.-As a thumb rule spans greater than 15 metres should be avoided however, much greater spans can be achieved by reinforcing the fabric with webbing or cables.-These loads have to be transmitted into our support structure.-A support structure might be edge tripods, central masts or push-ups; we might decide to suspend the fabric in some form to give a very large mast free area.

FABRIC TO SUPPORT SYSTEM CONNECTIONS:-Care must be taken not only to provide a path for the load to easily flow into the support structure but to allow flexibility in the connections for displacement and rotation.-During the erection process the whole structure will probably experience loads greater than the snow and wind effects during its working life span.-This is because of the uneven load imposed as the structure is assembled and tensioned.-Some fabrics can develop creep or elongation due to the type of weave or coating on the weave, heat and moisture.-This should be considered during analysis and has a direct effect on the connection system.-Creep will induce a loss of pre-cast tension in the fabric which will in turn mean that it can develop pond of water on its surface and will flap in the wind.-This loss of tension is dangerous for the stability of the structure and if not regularly maintained will lead to a failure of its structure.-Connections from the fabric to the support system should always be adjustable.Teflon coated fabrics require re-tensioning once the fabric has settled over a period of a few weeks.

SUPPORTING FRAMEWORK:SUPPORTING FRAMEWORK MADE OF STEEL:The supporting steel frameworks used for textile membrane buildings are convincing due to various characteristics:-Using different steel qualities, high yield, yet filigree constructions can be designed.-Wide range of variations as regards integration of suitable connection details -Factory prefabricationSince the standard profiles used in structural steel engineering are less suitable for textile building, special pipes and welding structures are manufactured in accordance with the project specific load and design requirements.The material quality (standard steel or high tensile steel) meets the static calculation. In order to achieve transportable individual sizes and to avoid on site welding, the steel framework elements usually are designed as screwed structures.For anticorrosion purposes, mostly the galvanized design is selected; the same applies for connection elements and fasteners.From a visual perspective an additional colour coating is recommended.In this case of stainless steel and aluminium, specific attention has to be directed to the material specific properties in the development of the forms as well as the structural design.SUPPORTING FRAMEWORK MADE OF BONDED TIMBER TRUSSES:-Particularly for the use of parallel and symmetric structures, also supporting frames made of bonded timber trusses provide a useful choice.-Since bonded timber trusses usually are designed to absorb high vertical loads, a combination with steel elements taking up the tensile force is required.-To avoid corrosion problems due to condensed water, sufficient ventilation has to be ensured when using timber designs.

SUPPORTING FRAMEWORK WITH REINFORCED CONCRETE:This choice is usually restricted to basic structures to avoid disturbing the lightness of the membrane roofing by an excess of massive supporting elements SUPPORTING ROPE

FRAMEWORK:-Usually combined with steel columns, supporting rope frameworks are ideal within the scope of textile building designs.-On the other hand, the filigree visual effect of the carrying ropes supports the aesthetics of the membrane constructions; on the other hand, the typical forms and form modifications typical for textile architecture can be achieved by outside loads due to the possible tension loads of ropes.-Rope nets can be used to statically support the membrane surfaces and by doing so open up the possibility to crate even larger, column less roofings.-As a rule, flexible spiral ropes in galvanized design are being used.-Applications are peripheral ropes, carrying ropes, anchoring ropes for columns, etc. As carrying ropes for larger structures, generally fully locked coil ropes are used whose individual strands are hot-galvanized.-To meet the characteristics of textile building, adjustable pressed on terminal fittings are used.-These terminal fittings-as well as all the ropes-can be made of stainless steel.-As an Alternative to steel ropes, high tensile aramide ropes can also be used, thereby providing a reduction in weight of more than 50% with the same tensile strength.-Although the costs for the aramide ropes are still above those for stainless steel ropes, they cannot be beaten if indeed a filigree design is required (e.g. for structures trussed with sag rods or in interior spaces).-Specifically designed for tying guy wires off or wrapping the fabric onto chain link fence, cable or rope, the large surface area ensures your material will not be damaged when pulled taut.-They have 2 front holes for maximum versatility. Small 3/16 hole at top for hook or screw and a larger 5/16 hole in middle for lag bolt. The pass through opening across top/centre will hold up to 5/16 diameter cable or rope.

SUPPORTING ROPE FRAMEWORK:-Usually combined with steel columns, supporting rope frameworks are ideal within the scope of textile building designs.-On the other hand, the filigree visual effect of the carrying ropes supports the aesthetics of the membrane constructions; on the other hand, the typical forms and form modifications typical for textile architecture can be achieved by outside loads due to the possible tension loads of ropes.-Rope nets can be used to statically support the membrane surfaces and by doing so open up the possibility to crate even larger, column less roofings.-As a rule, flexible spiral ropes in galvanized design are being used.-Applications are peripheral ropes, carrying ropes, anchoring ropes for columns, etc. As carrying ropes for larger structures, generally fully locked coil ropes are used whose individual strands are hot-galvanized.-To meet the characteristics of textile building, adjustable pressed on terminal fittings are used.-These terminal fittings-as well as all the ropes-can be made of stainless steel.-As an Alternative to steel ropes, high tensile aramide ropes can also be used, thereby providing a reduction in weight of more than 50% with the same tensile strength.-Although the costs for the aramide ropes are still above those for stainless steel ropes, they cannot be beaten if indeed a filigree design is required (e.g. for structures trussed with sag rods or in interior spaces).-Specifically designed for tying guy wires off or wrapping the fabric onto chain link fence, cable or rope, the large surface area ensures your material will not be damaged when pulled taut.-They have 2 front holes for maximum versatility. Small 3/16 hole at top for hook or screw and a larger 5/16 hole in middle for lag bolt. The pass through opening across top/centre will hold up to 5/16 diameter cable or rope.

CONCLUSIONS: Tensile fabric structure is a need for any developing city today. The development of tensile fabric structures has been in response to achieving permanent structures, which can span large areas and provide column free spaces as well as satisfying an aesthetic requirement. They perform a structural as well as architectural function. Structure and form are not separate elements in the case of tensile structures, they are an integral whole. The advantage of tensile structure lies in their inspiring forms and their inherent property to cover large spans by using visually and physically lightweight elements. Their principal advantage is the optimization of the material and flexibility of use. They offer an extremely appropriate form sympathetic to human environment at any scale of building. Under any design consideration, they harmonize with nature with nature and do not leave any presence or solid mark.

REFERENCES:BIBLIOGRAPHY:INDIAN ARCHITECT-special focus-TENSILE (may-2000)INTERNET-www.google.comhttp://www.tensiledesigns.comttp://www.taiyomembrane.inwww.basestructures.comwww.grotal.comwww.concat.in/