Space Frames

DEFINITION O In architecture and structural engineering, a space

frame or space structure is a truss-like, lightweight

rigid structure constructed from interlocking struts in

a geometric pattern.

O Space frames can be used to span large areas with

few interior supports.

O Like the truss, a space frame is strong because of

the inherent rigidity of the triangle;

flexing loads (bending moments) are transmitted

as tension and compression loads along the length

of each strut.

O It was developed by Alexander Graham Bell and

Buckminster Fuller's, whose focus

was architectural structures.

INTRODUCTION O Space frames are essentially three dimensional trusses

able to span in two directions.

O Space frames are a common feature in modern building construction; they are often found in large roof spans in modernist commercial and industrial buildings.

O Single Span from 20m up to 50m (multispan over 50m)

O They may be flat for use as roofs, walls or inclined walls, or may be curved to form continuous barrel type roof geometries.

O Space frames allow for easy service distribution within their depth and can provide light elegant structural solutions.

OVERVIEW

o The simplest form of space frame is

a horizontal slab of

interlocking square

pyramids and tetrahedra built

from aluminium or tubular

steel struts.

o A stronger form is composed of

interlocking tetrahedral in which all

the struts have unit length.

o More complex variations change the

lengths of the struts to curve the

overall structure or may incorporate

other geometrical shapes.

MEMBERS

O Tubes

1. Circular hollow sections

2. Rectangular hollow sections

O Connectors 1. Tuball Node Connector

• A hollow sphere made of spheroidal graphite.

• The end of the hollow section member to be connected is fitted at its ends by welding.

• Connection from inside the cup is using bolt and nut.

2. Nodus Connector

O It can accept both rectangular and circular hollow sections and that the cladding can be fixed directly to the chords.

O Chord connectors have to be welded to the ends of the hollow members on site.

3. Triodetic Connector

O 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

matching

crimped ends.

4. Hemispherical Dome Connector

O Usually used for double layered domes.

O Has a span more than 40m.

O More economical for long span.

O The joint is connected by slitting the end of

the tube or rod with the joint fin.

O There are two types of joints, pentagonal

joint and hexagonal joint.

CURVATURE CLASSIFICATION O Barrel vaults. This type of vault has a cross section of a simple arch. Usually this type of space frame does not need to use tetrahedral modules or pyramids as a part of its backing.

O Spherical domes Spherical domes and other compound curves usually require the use of tetrahedral modules or pyramids and additional support from a skin.

CLASSIFICATION IN TERMS OF ARRANGEMENT OF ELEMENTS

O Single layer grid.

All elements are located on the surface to be approximated.

O Double layer grid.

The elements are organized in two parallel layers with each other at a certain distance apart. Each of the layers form a lattice of triangles, squares or hexagons in which the projection of the nodes in a layer may overlap or be displaced relative to each other. The diagonal bars connect the nodes of both layers in different directions in space.

O Triple layer grid.

Elements are placed in three parallel layers, linked by the diagonals. They are almost always flat.

APPLICATIONS O Aircraft hangers.

O Factories, Hospitals.

O Cinema halls, Convention Centers.

O Malls, Exhibition halls,

O Airports, Hotels.

O Canopies.

O Transport Terminals. Schools, Pools, Arenas,

Entertainment, Corporate & Commercial Buildings.

ADVANTAGES OF SPACE-FRAMES

O Large spans with cantilevers can be achieved.

O Light i.e., minimum structure weight.

O Carry load by three dimensional action.

O Concentrated loads are evenly distributed on the entire structure.

O High inherent stiffness.

O Pre-finished to avoid site painting & inspection and also easy to construct.

O Pleasing decorative appearance.

O Pre-assembly allows project acceleration in turn, saves construction time and cost.

O Fast installation at site due to pre-fabricated components. Allows simple modification or dis-assembly for re-use.

O Very good acoustical properties.

O All service lines can run through frame.

O Space Frame can be a feature without ceiling.

O Suit irregular support or plan geometry.

O Variable depth for roof drainage is built-in.

BILBAO EXHIBITION CENTRE, SPAIN

ECOSPHERE MUSEUM, ISRAEL

STANSTED AIRPORT, BY FOSTER AND PARTNERS, LONDON

Jacob K. Javits

Convention Center, New

York City, New York

Louvre Pyramid and Bank of China Tower by I. M. Pei

Eden Project in Cornwall, England

Globen, Sweden - Dome with diameter of 110 m, (1989)

•Biosphere 2 by John P Allen Phil

Hawes Peter Jon Pearce in Oracle,

Arizona