A space frame or space structure is a truss-like, lightweight rigid structure constructed from interlocking struts in a geometric pattern. Space frames can be used to span large areas with few interior supports. Like the truss, a space frame is strong because of the inherent rigidity of the triangle; flexing loads (bending mo-ments) are transmitted as tension and compression loads along the length of each strut.
One of the prime reason for the growing popularity of this technology is the systems is the ability to modify the utilization of space by providing freedom of movement. This is achieved through column-free construction. The structure is three dimensional which is made from steel. But it is not only limited to that there are several types of it. This structure might be lightweight, but these structures can carry a much heavier load with a huge spanning capacity. The system can be arranged in a flat or curved shape that enhances the design flexibility of a structure and ensures load transfer. Right from the design to the erection phase to ensure the creation of structures this system offers high resistibility.
Space Frames can span large spatial area without intermediate columns by interlocking struts in a geometric pattern which is extremely useful in projects like Coal, Cement & Sugar Storage Domes, Sports Stadiums, Airports, and Shopping Malls etc. It can also form architectural marvels in long Skywalks, Pedestrian Bridges and can add aesthetic, rigidity and long life to smaller span structures like Metro Railway Stations, Swimming Pool covers, Toll Gates, Border Security Gates, Petrol / Gas Stations.
Space Frame Applications
The integrated terminal buildings are designed with a number of structural innovations. The key feature of airport structure is their long span roof covering with massive column spacing.
– Commercial and industrial structures
– Sky lights
– Toll booths
– Exhibition halls
– Sports stadiums
Edge of Space Frames
– The quality of roofs of this system is extremely good and the chances of deflection is almost nil
– The installation of the structure can be done with the help of a mobile scaffold in places where a crane cannot be used. Since light weight tube elements & spherical balls forming the space frame system, it can be lifted by human effort
– The space frames can cross large spans in both directions unlike the conventional ones. This gives great versatility and freedom to the designer in the selection of the structural system
– The 3d system used in the system gratification ensures the correct utility rate of materials which ensures huge saving in steel usage
– Since the system is prefabricated under factory supervision one can expect the rightful quality control
– Steel or concrete substructures can easily be integrated with the Space frames
– Minimal erection time as every component is fabricated
– Storage and transportation of the system components are quite economical
– The actual weight of steel membranes for large spans are less
– The multi-directional structural behavior grants unusual design
– The system is very convenient to fix any kind of cladding on the top by bolting down into the threaded hole provided at the top of each nodal joint
– The system offers flexibility to fix the light fixtures and ceiling systems
– By this method large span and big areas can be installed in shortened time period
– Since the self-weight of space frame is small, greater economy is gained in the substructures as an added advantage
– It is possible to integrate space frames in the architectural designs of various building types
– When required the space structure system can be easily demounted and rebuilt them at another location
– Space frame structures can be cladded with sandwich panels, acrylic, polycarbonate or glass glazing and will present a very modern and aesthetic view from both indoors and outdoors
– In regard to attachments, it can be cladded with galvanized steel, aluminium, skylights, sandwich panels, fabric structures etc
Why choose the 3D Space Frame Structures?
Structural efficiency, rigidity, reduced deflections, integration of services, resilience, ease & speed of manufacturing and installation are some of the biggest advantage of 3D Space Frame Structures.
– Due to the 3D nature of space frame system long and clear spans up to 180 m can be easily achieved in lightweight steel construction, whereas this is extremely difficult in conventional structures, if done with difficulty they will be heavier by two or three fold compared to space frames.
– Since space frames are factory produced as light weight components maximum 3.5 m length, they can be Hot Dip Galvanized in Molten Zinc bath and over the galvanized surface they are further protected by either by powder coat or liquid spray paint to protect the entire structure from corrosion especially when serviced in extremely corrosive environment ( ie Corrosion Class 4 (Near Sea, Chemical Industries etc.), this coating system can warrant for a period of 20 years for first maintenance of the coating work on structure.
– Conventional trusses, steel sections used are longer compared to Space frame components so Hot Dip Galvanizing and powder coating on these items are often not practical hence their corrosion resistance is weak demands regular maintenance and may lead to premature failures.
– The open nature of the structure between the two plane grids allows easy installation of mechanical and electrical services and air-conditioning ducts, sprinkler system, fire fighting services etc. within the structural depth of the modular construction.
– Their fixing is simplified as there is a regular grid of supports available thus reducing or even eliminating the need for secondary steelwork to support them.
Protection against corrosion and fire
Space structure system appears as structurally sealed circular hollow sections concentrically connected to solid spherical steel nodes stands out as a superior aesthetic and architectural end product. The exposed surfaces of space frame members are powder coated to decorative colour finish in a factory controlled environment. The most modern and automated zinc phosphate treatment/ powder coating technology provides weather and abrasion resistant thermoset polyester coatings in various eye catching colours selected from German colour Standard RAL Or Internationally accepted NCS.
When specified to be fire protected, the exterior exposed surface of the components is spray coated with UL certified intumescent paint for minimum one hour fire rating. In such cases, the space structure is designed to select the optimum size and thickness of each element in the structure for the required HP/A value that is Heated Perimeter to Cross sectional Area to achieve a minimum fire rating of 60 minutes. If there is no specific fire rating required, then the structure designed as standard space frame as per project specified loadings as well as design codes and a UL certified intumescent paint is coated as recommended by the coating manufacturer.
Design and Installation
In-house developed structures by the expert companies are so designed nowadays that it can perform specified tasks of structural analysis to international codes AISC, ANSI, ASCE, etc. as well it can generate manufacturing data and installation drawings to ensure speed and accuracy throughout construction.
The method chosen for the installation of space frame depends on its behaviour of load transmission and construction details, so that it will meet the overall requirements of quality, safety, speed of construction and economy. The options available are three.
– Scaffold Method – Individuals Elements are Assembled in Place at actual Elevations, members and joints or prefabricated subassembly elements are assembled directly on their final position.
– Block Assembly Method – The Space frame is divided on its plan into individual strips or blocks These units are fabricated on the ground level, then hoisted up into final position and assembled on the temporary supports.
– Lift-up Method – The whole space frame is assembled at ground level so that most of the work can be done before hoisting.
Advantage of Space frame Structure over Conventional and Pre-Engineering Steel Roof Structure
– Space Frame Structures can be fixed and dismantled as per need and desire
– The structure is beautiful in look and in case of structure it is very safe for shorter to longer period
– This structure is every architectures delight as this system, enables work of any kind of geometrical shape and profile
– In this structure the distribution if lighting is very convenient as there is a presence of nodes and balls over the full complete area. In this system, AC ducts, Fire Sprinkler system can pass through the without requiring additional space and false ceilings,
– Load transfer in this structure is completely apt due to concentric and zero eccentric connections in axials
– All the space frames pipes( hollow space) and components are perfectly protected against atmospheric exposure and attacks in this type of structure
– For better corrosion resistance in the system, Galvanized product can be obtained with powder coating
– This structure is anti- quake as the dead loads (Mass Lumps) are distributed over many joints/nodes which lead to no or minimal loss of the structure during tremors and earthquakes
– Structural integrity and global ductility is superior in this system
– This structure is capable of taking heavier loads from roof of steel roofed buildings
– The space frame structure provides wide working floor area without any obstruction through intermediate supporting columns
– This system is highly suited for shopping malls, Auditoriums, Function Halls, Stadiums, factory buildings, pedestrian bridges, Railway stations, Airport terminal buildings etc
– This system when adopted for small structures like Pargolas , Entrance gate arches, the structure gives elegant and rich look with excellent aesthetic appearance
– The space frame structure is considered as hinged and hence supporting media (Concrete or steel columns and foundations) are economical as there is no moment transfer from SF to Supporting media
According to business-standard.com report, The structural steel buildings market in India was around 5.0 to 5.5 million MT in 2011, of which around 9.5-10% accounted for the PEB market in India. It is expected that the market in terms of volumes will reach 9,00,000 MT by 2016, at CAGR of 11.1%. The PEB market is strongly associated with investments and growth in the industrial and commercial sectors. The new potential application areas for steel frame system in the next few years will include power plant structures, factory buildings, commercial buildings (offices and retail malls), warehouses, and metro stations.
Due to its geometrical versatility, interdependence and continuity information the design forces are well distributed throughout the building process in this system..With the onset and speedy progress of the commercial buildings in the next 10 years, the scope of Space Frame is immense. The increase in technical competence plays a crucial role, and many market participants have introduced high-grade steel conforming which attracted many customers to pay high prices for quality jobs. The heightened emphasis on green building construction is also poised to push market expansion. This system is yet to reach its full potential but it is going to captivate the market in the coming days.