GEODESIC DOMES

SUBMITTED BY :KARAN 12609ASHNA 12635ADEEBA 12636RUBY 12637

A Geodesic Dome is a particular type of structure shaped like a part of a sphere or a ball.The geodesic system consists of dividing a sphere into equal triangles so that the surface structure of a dome could be more easily made.The similarity of the triangles makes the domes easier to construct and benefits by being structurally strong. The overall strength is distributed evenly.

• An American engineer called Richard Buckminster Fuller in the 1940's invented the geodesic dome

• Fuller's ambition was to create a 'design science' that would be able to create the best solutions to problems with minimal consumption of energy and materials.

• The word geodesic comes from a Latin word meaning 'earth dividing'. Buckminster Fuller invented the Geodesic Dome in the late 1940s to demonstrate some ideas he had about housing and 'energetic-synergetic geometry' (two types of structures or geometry working together to create a new stronger structure), which he had developed during the Second World War

Geometry

• The geometry is based on an icosahedron whose triangular faces are then subdivided into smaller triangles. An icosahedron has twenty faces, each of which is an equilateral triangle and therefore all of the triangles are the same size.

• Triangles are structurally very strong. If you lean on one of the corners of a triangle made from three pipes bolted together, the only way it can collapse is if one of the pipes actually buckles or if a nut completely shears off of a bolt. It's much stronger than a rectangle; a rectangle of pipes and bolts could collapse if the bolts slip, which is much more likely than a shear.

An icosahedron appears to have a cap and then a base made up of five triangles all sharing the top and bottom points, respectively. Ten triangles connect the cap and base

The force put into a corner of a triangle is directly transmitted to the base of the triangle. Since an icosahedron is made up of triangles, the force is distributed throughout the shape. The icosahedron can collapse from one of the joints between separate triangles bending, but that's still a very strong structure

To make an icosahedron approximate a sphere more closely, the triangles making up the icosahedron are subdivided by splitting the edges of the triangle and then making the new split edges into more triangles

The popular notation on the web for this seems to be mV, where m is the number of new edges made from each original edge, like 2v, 3v, 4v, etc...

If the corners of the new triangles are then moved out to the surface of a sphere centered on the icosahedron, you get something that looks more and more like a sphere the more the triangles are split. These are called "geodesic spheres".

A triangle whose edges are split into 2; the result is 4 triangles

A triangle whose edges are split into 3; the result is 9triangles

A triangle whose edges are split into4; the result is 16triangles

Spheres with an odd degree (1v, 3v, 5v, etc...) can't actually be cut exactly in half

A 2v geodesic sphere (80 triangles

A 3v geodesic sphere(180 triangles)

A 2v geodesic dome A "3/8" 3v geodesic dome A "5/8" 3v geodesic dome

A 4v geodesic sphere(320 triangles)

A 10v geodesic sphere(2000 triangles)

A 4v geodesic dome A 10v geodesic dome

Actually Building a Dome The process of splitting the triangles and then moving ("projecting") the corners out to the surface of a sphere is that the edges change so they are no longer equal lengths. Thus the triangles are no longer equilateral.

sites like ”Desert Domes” are so useful to dome builders; the Desert Domes site provides the ratios of strut lengths for domes

There are only three unique lengths; 1.00, 1.15, and 1.18 meters

A 3v triangle before projection

A 3v triangle after projection

Lengths of edges of projected triangles

Edges colored by length

1.18

1.15

1

• to cut lengths of pipe, • crimp the ends, • drill holes through the ends, • then bolt all the pipes

together at the dome corners.

1.18

1.15

1

View of 3vdome colored by strut length

Layout map of dome struts colored by length

EDEN PROJECT - A LIVING THEATRE OF PLANTS IN THE

HEART OF CORNWALL

SITE PLAN

The complex is dominated by two huge enclosures consisting of adjoining domes that house thousands of plant species, and each enclosure emulates a natural biome.

The first dome simulates a tropical environment, and the second a Mediterranean environment.

TWO DOMES

AREA - 1.56 ha HEIGHT - 55 mWIDTH - 100 m LENGTH - 200 m

THE TROPICAL BIOME

AREA - 0.654 haHEIGHT - 35 mWIDTH - 65m LENGTH – 135m

THE MEDITERRANEAN BIOME

STRUCTURE

• The outer layer is made of hexagons (the largest is 11m across.

• The inner layer comprises hexagons and triangles bolted together.

The covered biomes are constructed from a tubular steel (hex-tri-hex) in two layers.

MATERIAL

The cladding panels are created from several layers of thin UV-transparent ETFE film, which inflated to create a two-metre-deep pillow.

External cladding panels are made from the thermoplastic ethylene tetra fluoroethylene copolymer (ETFE).

Although our ETFE windows are very light (less than 1% of the equivalent area of glass) they are strong enough to take the weight of a car.

ADVANTAGE • Lower initial cost• A safe construction-Stable, strong and solid• Lightweight construction & good strength • Quick assembly time compared with traditional constructions• Door and window openings are pre-framed for conventional doors and

windows on all 10 sides• Solar Heating is possible.• Domes as tall as 50 meters are constructed in the wilderness from rough

materials without a crane.• It can withstand hurricane-strong winds

DISADVANTAGE

• The dome's shape can create problems in placing sewer vents and chimneys.• Fire escapes are expensive and a must for large buildings like this.• Moisture in the dome are usually not heard of and therefore if any enters, the

dome quickly dissolves .• Sounds, smells, and lights can be seen throughout the entire structure due to

lack of privacy.• Wall areas are difficult to use due to the shape.• It is hard to seal the domes against rain.