Space frames-modular construction technology

1. SPACE FRAMES:
MODULAR CONSTRUCTION
TECHNOLOGY
PREPARED BY:
SHERYL
SEM VI
KMEA COLLEGE OF ARCHITECTURE

2. • A space frame or space structure is a truss-like, lightweight rigid structure constructed from interlocking struts
in a geometric pattern.
• span large areas with few interior supports.
• Inherent rigidity of the triangle; flexing loads ( bending moments ) are transmitted as tension and
compression loads along the length of each strut.
• Simplest form – horizontal slab of interlocking square pyramids and tetrahedral built from aluminium or
tubular steel struts.
SPACE FRAMES

3. HISTORICAL BACKGROUND
• Space frames were independently developed by Alexander Graham Bell around 1900 and Buckminster Fuller
in the 1950s.
• Bell – using them to make rigid frames for nautical and aeronautical engineering, with the tetrahedral truss
being one of his inventions.
• Fuller – architectural structures and his work had greater influence.

4. APPLICATIONS
• For a platform overhead structure that spans large
distances without need for internal load bearing
support.
• New and imaginative applications are being
demonstrated in the total range of building types ,
such as sports arenas
exhibition pavilions,
assembly halls,
transportation terminals,
airplane hangars,
workshops, and warehouses.
• Also used on mid and short span enclosure as roofs ,
floors, and exterior walls.

5. ADVANTAGES
lightweight The material is distributed spatially in such a way that
the load transfer mechanism is primarily axial; tension
and compression.
Consequently, all material in any given element is
utilized to its full extent.
Aluminium decreases considerably their self-weight.
Mass productivity Can be built from simple prefabricated units, which are
often of standard size and shape.
Easily transported
Rapidly assembled on site.
Therefore it can be built at lower cost.
stiffness Sufficiently stiff in spite of its lightness.
This is due to its three-dimensional character and to
the full participation of its constituent elements.
versatility Possess a versatility of shape and form and can utilize a
standard module to generate various flat space grids,
latticed shell, or even free-form shapes.

6. STRUCTURAL BACKGROUND
• A long spanning three dimensional structure
• Rigidity of the triangle
• Composed of linear elements subject only to axial tension
or compression
• The influence of bending moment is insignificant.
• The span-depth ratio varies from 12.5 to 25, or even more.
• The depth can be relatively small when compared with
more conventional structures.

7. TYPES OF SPACE FRAMES
Flat covers Barrel vaults Spherical domes
Composed of planar substructures.
The plane are channelled through the
horizontal bars and the shear forces
are supported by the diagonals.
This type of vault has a cross section
of a simple arch form.
Usually does not need to use
tetrahedral modules or pyramids as a
part of its backing
Usually require the use of tetrahedral
modules or pyramids and additional
support from a skin.

8. ACCORDING TO THE NUMBER OF GRID LAYERS
Single layer Double layer Triple layer
All elements are located on the
surface to be approximated.
Organised in two parallel layers with
each other at a certain distance
apart.
The diagonal bars connecting the
nodes of both layers in different
directions in space
Placed in three parallel layers ,
linked by the diagonals.
Almost always flat.
This solution is to decrease diagonal
members length.

9. COMPONENTS
Members Joints
Axial elements with circular or rectangular sections , all
members can only resist tension or compression.
The space grid is built of relatively long tension members
and short compression members.
A trend in which the structural elements are left exposed as
a part of the architectural expression.
Connecting joints- both functional and aesthetic.
joints have a decisive effect on the strength and stiffness of
the structure and compose around 20-30 percent of the
total weight.
SPACE FRAME CONNECTIONS

10. DESIGN CONSIDERATIONS FOR DOUBLE LAYER

12. MERO SPACE FRAME SYSTEM
• The Mero connector, introduced in 1948 by Dr, Mongeringhausen , proved to
be extremely popular and has been used for numerous temporary and
permanent buildings.
• Its joint consist of a node that is a spherical hot-presses steel forging with flat
facets and tapped holes.
• Members are circular hollow sections with cone-shaped steel forging welded
at the ends, which accommodate connecting bolts.
• Originally developed for double-layer grids.
• Due to the increasing use of non-planar roof forms- load bearing space frame
integrated with the cladding element.
• A new type of joining system called Mero Plus System was developed so that
a variety of curved and folded structures are possible.

13. METHODS OF ERECTION
Scaffold method Block Assembly method Lift-up method
Individual elements are assembled in
place at actual elevations
Members and joints or prefab
subassembly elements are assembled
on their final position.
Full scaffoldings usually.
Sometimes partial scaffolding are used if
cantilever erection.
Elements fabricated at the shop
Transported to the construction site,
and no heavy lifting equipment is
required.
Divided on its plan into individual strips
or blocks.
These units fabricated on the ground
level. Then hoisted upon into its final
position and assembled on the
temporary supports.
Suitable for double layer grids.
The whole space frame is assembled at
the ground level so that most of the
work can be done before hoisting.
Increased efficiency and better quality.

15. Space frame
To accommodate large unobstructed areas
Satisfying the requirements for lightness, economy and speedy construction
Its great structural potential and visual beauty
Demand for large space with minimum interference from internal supports
Difficulty of the complicated analysis of such a system has contributed to its limited use
APPLICATIONS : Sport arenas
Exhibition pavilions
Assembly halls
Transportation terminals
Airplane hangars
Workshops
Warehouses
Long span,mid and short span enclosures as roofs, exterior walls , and canopies.

17. SINGLE AND DOUBLE LAYER
• a flat or a curved surface.
• Earliest form is single-layer grid.
• By adding intermediate grids and including rigid
connection to the joist and girder framing system.
• The major characteristic of grid construction is the
omnidirectional spread of the load as opposed to the
linear transfer of the load in an ordinary framing
system.
• Since such load transfer is mainly by bending, for large
spans the bending stiffness is increased most
efficiently by changing to a double-layer system.
• The load transfer mechanism of a curved surface from
the grid system that is primarily membrane-like action.
LOAD TRANSER planar structures
and space frames
• In a planar system, the force due to the roof
load is transferred through the secondary
elements, the primary elements, and then
finally to the foundation.
• Ina space frame system, there is no sequence
of load transfer, and all elements contribute to
the task of resisting the roof load in accordance
with the three-dimensional geometry of the
structure.

18. LOAD TRANSFER
• Designing a roof structure for a square
building.
• A complex roof composed of planar latticed
trusses. Each truss resists the load acting on
it independently and transfers the load to
the columns on each end.
• Latticed trusses are laid orthogonally to
form a system space latticed grids that will
resist the roof load through its integrated
action as a whole and transfer the loads to
the columns along the perimeters.
• Since the loads can be taken by the
members in three dimensions, the
corresponding forces in space latticed grids
are usually less than in planar trusses and
hence depth can be decreased in a space
frame.

19. LOAD TRANSFER
• Designing of a circular dome.
• A complex of elements like arches,
primary and secondary beams and
purlins which all lie in a plane. Each of
the elements constitutes a system that is
stable by itself.
• An assembly of a series of longitudinal,
meridional and diagonal members, a
form of latticed shell.

20. ADVANTAGES
• Lightweight
• distributed spatially, load
transfer mechanism is primarily
axial- tension or compression.
• steel, aluminium.
• Prefabricated , easily transported
and rapidly assembled. Can be
built at a lower cost.
• Sufficiently stiff.
• versatile

21. DOUBLE-LAYER GRIDS