a space frame or space structure is a rigid, lightweight, truss-like structure constructed from interlocking struts in a geometric pattern. Space frames can be used to span large areas with few interior support

1. SPACE FRAME

2. A space frame is a structure system assembled of linear
elements so arranged that forces are transferred in a
three-dimensional manner. In some cases, the constituent
element may be two dimensional.

3. Deflection of a system of individual trusses

4. Deflection of a system of individual trusses Deflection of a two-way spanning double-layer grid of
intersecting trusses demonstrating the load distribution
advantage of the latter

6. Load sharing
• THE advantage of space grid structures is that generally all elements
contribute to the load carrying capacity. Planar beams or trusses must be
capable, individually, of carrying any possible concentrated or heavy
moving loads (e.g. overhead cranes). However, in space grids such
concentrated loads are distributed more evenly throughout the structure
and to all the supports. This can also reduce the cost of the supporting
structures as maximum column and foundation loads may be less.
Maximum deflections are reduced compared to plane structures of
equivalent span, depth and applied loading, assuming that the structural
elements are of similar size. Alternatively, a lighter or shallower three-
dimensional structure may be used to carry the same loads, resulting in
maximum deflections no greater than those of a planar structure.

7. Advantages of using space grids
• Load sharing
• Installation of services
In space grids, the reasonably open nature of the structure between the two plane grids allows easy
installation of mechanical and electrical services and air-handling ducts within the structural depth.
• Robustness
Space grids are highly redundant structures, which means that, in general, failure of one or a limited
number of elements – for instance, the buckling of a compression member under excessive loading –
does not necessarily lead to overall collapse of the structure.
• Modular components
Space grids are highly modular structures assembled from components that are almost exclusively factory
fabricated. The components therefore, are usually produced with high dimensional accuracy, with a high quality
of surface finish and they are generally easily transportable, requiring little further work except assembly on site.
Because of their modular nature, space grids may be xtended without difficulty and even taken down and
reassembled elsewhere.

8. Advantages of using space grids
• Freedom of choice of support locations
Great choice in the location of supports is offered by space grid structures. Within reason, space
grids can be supported at any node of the grid and at practically any location in plan.
• Regular geometry
For ease of construction, most space grids have a regular pattern that may be exploited architecturally to
some effect. Particularly striking effects can be achieved if the colour chosen for the structural members
contrasts with the colour of the decking, or with the sky in the case of unclad grids or fully glazed
applications.
• Ease of erection
A further advantage of the use of space grids is the efficiency of erection for large-span roof structures
and especially
on sites with limited access. In the former case, the whole roof can be assembled safely at or near ground
level, complete with decking and services, and then jacked into its final position. In the latter case, the
small components of a space grid can be assembled at almost any location using only manual labour and
simple lightweight tools, even inside existing buildings.

9. Disadvantages
Cost
cost, which can sometimes be high when compared with alternative structural systems such as
portal frames. This disparity in cost is particularly evident when space grids are used for relatively
short spans, although the definition of a short span is very dependent on the system under
consideration. However, spans of less than 20 to 30 m can probably be considered short
Regular geometry
Although the regular geometry of space grids is generally cited as one of their appealing features, to
some eyes they can appear very ‘busy’.
Erection time
Again, this is a topic that also appears under the list of advantages. However, another common
criticism of space grids is that the number and complexity of joints can lead to longer erection times
on site.
Fire protection
Space grids are mainly used in roof construction where, depending on the materials involved,
nominal or no fire resistance is normally required. However, when they are used to support floors,
some form of protection is usually demanded to provide the necessary fire resistance, if they are
exposed. This protection is difficult to achieve economically due to the high number and relatively
large surface area of the space grid elements, but intumescent coatings can be applied.

10. Space truss stability
• The stability of rigid jointed space frames depends on the bending
resistance of the joints for its structural integrity. However, space
truss structures depend on their geometrical configuration to ensure
stability. A fully triangulated structure must be formed.
• In a three-dimensional pin-jointed space truss structure, it is a
necessary condition for stability, (variously known as Maxwell’s
Equation or Foppl’s Principle), that,

12. TYPES OF SPACE FRAME
1) Two and three-way grids
• Characterized as two way or
three way
2) Single, Double and Triple
Layered
• Single layer frame has to be
singly or doubly curved.
• Commonly used space
frames are double layered
and flat.
• Triple layered is practically
used for a large span
building.

15. Double layer grid type
Two-way space grid with
square and three way space
grid with triangular pyramid
Two-way space grid with
square and three way space
grid with tetrahedral unit
Two-way and three way lattice
grid

16. (a) Uniform curved camber formed by slightly shortening all of the lower chord members in one direction,
(b) ridge camber formed by shortening one lower chord member in one direction under the ridge,
(c) stepped curved camber formed by slightly shortening the lower chord members in one direction at regular bay
intervals and
(d) freeform curve generated by suitable manipulation of top and bottom chord lengths in one direction
SECTIONS

17. SUPPORT LOCATIONS

18. SUPPORT LOCATIONS

19. EDGE PROFILES

22. Four-point cruciform Frame capital
Top-chord supported Bottom-chord supported
Interior wall Exterior wall

23. Materials and systems

24. • STEEL
• ALUMINUM
• CONCRETE
• REINFORCED PLASTIC
• BAMBOO (EXPERIMENTAL PHASE)
• GLASS (SCULPTURE)

25. STEEL
• HIGH YIELD MILD STEEL ELEMENT , COLD-FORMED FROM STEEL STRIP
• CASTINGS FROM SPHEROIDAL GRAPHITE IRON
KNOWN AS DUPLEX SYSTEM IF BOTH THE MATERIALS ARE USED
THESE MEMBERS ARE GALVANISED OR PAINTED

26. Space frames may be
constructed of structural
steel pipe, tubing,
channels, tees, or W-
shapes.
• Fabricated connectors
join the members.
• Consult manufacturer for
details, module size,
and allowable spans.
Welded
connection
Bolted
connection
Threaded
connections

27. TYPES OF STEEL SPACE GRID SYSTEMS
• ASSEMBLED USING ‘PIECE-SMALL’ SYSTEMS
• ASSEMBLED USING CONTINUOUS CHORDS
• ASSEMBLED USING FACTORY PREFABRICATED MODULES

28. ‘PIECE-SMALL’ SYSTEMS
• The ‘piece-small’ systems primarily differ in the jointing method.
Most use circular or square hollow tube members because of their
better performance in resisting the forces present in space trusses.
1 Spherical nodes:
(a) solid
(b) hollow.
2 Cylindrical.
3 Prismatic.
4 Plates.
5 ‘Nodeless’.

29. Spherical nodes
• Solid cast steel spheres are drilled with threaded holes at the appropriate angle for connection of the
adjacent members and are machined to provide appropriate bearing surfaces. The attachment of each
member is usually achieved with a single bolt on its central axis. In some systems the ends of the members
come into direct contact with the nodes, whilst in others the axial forces are transmitted solely through the
connecting bolts.
Mero KK space truss system, FIRST COMMERCIALLY AVAILABLE PRODUCT FOR SPACE TRUSS
The original ‘ball’ joint, now known as the KK system, is a hot-forged solid steel sphere finished with 18
threaded holes and machined bearing surfaces at angles of 45°, 60° and 90° relative to each other.
With modern computer numerically controlled precision drilling techniques, holes may now be drilled at
almost any required angle rather than only at the standard angles, although there is a minimum angle of
35° specified between adjacent holes.

30. SEO SPACE FRAME SYSTEM
This connection system allows any bar to be removed easily from a completed grid at any time. By unscrewing
the sleeves at both ends of a member, the bolts retract inside the tube sufficiently to enable its
removal and replacement.

31. Hollow spherical nodes
Nodus Connector
• It can accept both rectangular and circular hollow
sections and that the cladding can be fixed directly
to the chords.
• Chord connectors have to be welded to the ends
of the hollow members on site.

32. Triodetic Connector
• It consists of a hub, usually an aluminium extrusion, that has slots or key
ways, which the ends of members are pressed or coined to match the slots.

33. Moduspan (Unistrut) node showing the coldformed members
bolted to the node plate

34. ‘Nodeless’ joints
Because the special separate node components usually represent a considerable proportion of the cost of a
40 Space Grid Structures space grid, some systems eliminate these completely, relying instead on direct
connection between the ends of the grid members. Although this saves in overall cost, it tends to limit the
possible configurations of the grid as the end connections of members are often designed to accommodate
standard angles between the parts.

35. CONTINUOUS CHORDS
A typical Harley Type
80 node joint
OTHER SYSTEM INCLUDES
Mai Sky System
Catrus

36. MODULAR SPACE TRUSS
The system is based on
pyramidal units that are
assembled from a square
frame of steel angles
connected by circular steel
tube bracing members to a
central cast steel boss. All
elements of the pyramids
are welded together in a
fabrication jig to ensure
consistent dimensional
accuracy.