Beam Bridge Models - Revision history

DT Online at 19:09, 12 October 2017

2017-10-12T19:09:02Z

← Older revision		Revision as of 19:09, 12 October 2017
Line 69:		Line 69:
	[[Category:Primary Technology]]		[[Category:Primary Technology]]
	[[Category:Topics, Projects and Tasks]]		[[Category:Topics, Projects and Tasks]]
			[[Category: Tasks]]
	[[Category:Structures Tasks]]		[[Category:Structures Tasks]]
	[[Category:Bridges]]		[[Category:Bridges]]
	[[Category:Beams]]		[[Category:Beams]]

DT Online at 10:13, 1 March 2017

2017-03-01T10:13:58Z

← Older revision		Revision as of 10:13, 1 March 2017
Line 21:		Line 21:
	*how deep was your beam?		*how deep was your beam?
	*what types of traffic or services could pass over your beam?		*what types of traffic or services could pass over your beam?
	. . . or even through your beam . . . the [http://en.wikipedia.org/wiki/Britannia_Bridge '''Britannia Bridge'''] across the '''Menai Strait''' was originally designed and built by [http://en.wikipedia.org/wiki/Robert_Stephenson '''Robert Stephenson'''] as a tubular bridge of [~~https~~://en.wikipedia.org/wiki/Wrought_iron '''Wrought Iron'''] rectangular box-sections for carrying rail traffic inside - but it had to be rebuilt following a fire in 1970.		. . . or even through your beam . . . the [http://en.wikipedia.org/wiki/Britannia_Bridge '''Britannia Bridge'''] across the '''Menai Strait''' was originally designed and built by [http://en.wikipedia.org/wiki/Robert_Stephenson '''Robert Stephenson'''] as a tubular bridge of [http://en.wikipedia.org/wiki/Wrought_iron '''Wrought Iron'''] rectangular box-sections for carrying rail traffic inside - but it had to be rebuilt following a fire in 1970.

	[[File:LoadedBeams2.png\|800px\|bottom]]		[[File:LoadedBeams2.png\|800px\|bottom]]

DT Online: Added Category

2016-11-23T09:17:18Z

Added Category

← Older revision		Revision as of 09:17, 23 November 2016
Line 68:		Line 68:

	[[Category:Primary Technology]]		[[Category:Primary Technology]]
			[[Category:Topics, Projects and Tasks]]
			[[Category:Structures Tasks]]
	[[Category:Bridges]]		[[Category:Bridges]]
	[[Category:Beams]]		[[Category:Beams]]
	~~[[Category:Structures Tasks]]~~

DT Online: Added Link

2016-06-09T13:09:18Z

Added Link

← Older revision		Revision as of 13:09, 9 June 2016
Line 21:		Line 21:
	*how deep was your beam?		*how deep was your beam?
	*what types of traffic or services could pass over your beam?		*what types of traffic or services could pass over your beam?
			. . . or even through your beam . . . the [http://en.wikipedia.org/wiki/Britannia_Bridge '''Britannia Bridge'''] across the '''Menai Strait''' was originally designed and built by [http://en.wikipedia.org/wiki/Robert_Stephenson '''Robert Stephenson'''] as a tubular bridge of [https://en.wikipedia.org/wiki/Wrought_iron '''Wrought Iron'''] rectangular box-sections for carrying rail traffic inside - but it had to be rebuilt following a fire in 1970.


	. . . or even through your beam . . . the [http://en.wikipedia.org/wiki/Britannia_Bridge '''Britannia Bridge'''] across the '''Menai Strait''' was originally designed and built by [http://en.wikipedia.org/wiki/Robert_Stephenson '''Robert Stephenson'''] as a tubular bridge of wrought iron rectangular box-section spans for carrying rail traffic inside but had to be rebuilt following a fire in 1970.
	[[File:LoadedBeams2.png\|800px\|bottom]]		[[File:LoadedBeams2.png\|800px\|bottom]]

Line 49:		Line 48:
	----		----
	<span style="color: green">'''Note:'''		<span style="color: green">'''Note:'''
	If beams or joists have to be drilled to accept pipes or wiring etc., it is best to pass them close to the Neutral Axis to avoiding weakening the beam		If beams or joists have to be drilled to accept pipes or wiring etc., it is best to pass them close to the Neutral Axis to avoiding weakening the beam. ''(For convenience, notches are often cut into the top surface of a floor joist to receive wires or domestic plumbing. This is usually acceptable providing they are small because the top is in '''[[Compression]]''' and this will tend to close them up. Notches cut into the bottom of joists should be avoided since this would create a potential fracture point as a result of the '''[[Tension\|Tensile Forces]]''' pulling it apart)''.
	</span>		</span>
	----		----

DT Online at 12:51, 9 June 2016

2016-06-09T12:51:11Z

← Older revision		Revision as of 12:51, 9 June 2016
Line 10:		Line 10:


	You can either add small weights to the top centre of the beam or suspend a paper cup or similar underneath. In either case you may wish to place a small section (say, 50mm square) of thicker card in the centre of the beam to spread the load a little.		You can either add small weights to the top centre of the beam or suspend a paper cup or similar underneath and slowly fill with sand. In either case you may wish to place a small section (say, 50mm square) of thicker card in the centre of the beam to spread the load a little.

DT Online: Added Template

2016-05-31T09:48:42Z

Added Template

← Older revision		Revision as of 09:48, 31 May 2016
Line 3:		Line 3:

	[[File:TestingPaperBeam2.png\|400px\|right]]		[[File:TestingPaperBeam2.png\|400px\|right]]
			__TOC__


			=====Description=====
	Place two wooden blocks or similar supports 250mm apart then design a beam bridge to span the gap between them using '''[[Paper and Card\|A4 paper]]''' or thin card. Try different designs and test each one by loading it until it fails.		Place two wooden blocks or similar supports 250mm apart then design a beam bridge to span the gap between them using '''[[Paper and Card\|A4 paper]]''' or thin card. Try different designs and test each one by loading it until it fails.

Line 8:		Line 12:
	You can either add small weights to the top centre of the beam or suspend a paper cup or similar underneath. In either case you may wish to place a small section (say, 50mm square) of thicker card in the centre of the beam to spread the load a little.		You can either add small weights to the top centre of the beam or suspend a paper cup or similar underneath. In either case you may wish to place a small section (say, 50mm square) of thicker card in the centre of the beam to spread the load a little.


			=====Testing=====

	Make a sketch of each design and record the results:		Make a sketch of each design and record the results:
Line 15:		Line 21:
	*how deep was your beam?		*how deep was your beam?
	*what types of traffic or services could pass over your beam?		*what types of traffic or services could pass over your beam?



Line 24:		Line 29:
	*was it the widest beams that were strongest or the deepest?		*was it the widest beams that were strongest or the deepest?


			=====Modern Steel Beams=====

	You will notice a difference if you try bending a ruler first on its side and then on edge. The steel girders or [http://en.wikipedia.org/wiki/Rolled_Steel_Joist '''joists'''] seen in building construction are often made in an 'I' section which is taller than it is wide. The narrow 'flanges' at top and bottom are there mainly to stop the beam buckling and twisting under load - and to provide a flat supporting surface.		You will notice a difference if you try bending a ruler first on its side and then on edge. The steel girders or [http://en.wikipedia.org/wiki/Rolled_Steel_Joist '''joists'''] seen in building construction are often made in an 'I' section which is taller than it is wide. The narrow 'flanges' at top and bottom are there mainly to stop the beam buckling and twisting under load - and to provide a flat supporting surface.
Line 45:		Line 52:
	</span>		</span>
	----		----

			=====Traditional Timber Beams=====

	[[File:Cleaving.jpg\|200px\|right\|Cleaving a 'green' tree trunk using axe and wedges\|link=http://en.wikipedia.org/wiki/Cleaving_axe]]		[[File:Cleaving.jpg\|200px\|right\|Cleaving a 'green' tree trunk using axe and wedges\|link=http://en.wikipedia.org/wiki/Cleaving_axe]]
	In contrast to modern practice, if you look inside a Medieval [http://en.wikipedia.org/wiki/Timber_framing '''timber-framed'''] house, such as the [http://en.wikipedia.org/wiki/Merchant_Adventurers%27_Hall '''Merchant Adventurers' Hall'''] in York for example, you will notice that roof and floor beams are often wider than they are deep.		In contrast to modern practice, if you look inside a Medieval [http://en.wikipedia.org/wiki/Timber_framing '''timber-framed'''] house, such as the [http://en.wikipedia.org/wiki/Merchant_Adventurers%27_Hall '''Merchant Adventurers' Hall'''] in York for example, you will notice that roof and floor beams are often wider than they are deep.
Line 53:		Line 63:

	The result is a very heavy and over-sized beam - but trees at that time were plentiful!		The result is a very heavy and over-sized beam - but trees at that time were plentiful!


			{{Card Modelling Buyers Guide}}


	[[Category:Primary Technology]]		[[Category:Primary Technology]]

DT Online: Added Category

2016-03-28T18:02:36Z

Added Category

← Older revision		Revision as of 18:02, 28 March 2016
Line 54:		Line 54:
	The result is a very heavy and over-sized beam - but trees at that time were plentiful!		The result is a very heavy and over-sized beam - but trees at that time were plentiful!

			[[Category:Primary Technology]]
	[[Category:Bridges]]		[[Category:Bridges]]
	[[Category:Beams]]		[[Category:Beams]]
	[[Category:Structures Tasks]]		[[Category:Structures Tasks]]

DT Online: Added Alt text and link to images

2015-12-19T12:17:20Z

Added Alt text and link to images

← Older revision		Revision as of 12:17, 19 December 2015
Line 31:		Line 31:


	[[File:CastellatedBeam.png\|300px\|right]]		[[File:CastellatedBeam.png\|300px\|right\|Castellated Beam]]
	In a [http://en.wikipedia.org/wiki/Rolled_Steel_Joist '''Castellated Beam'''], these are created by cutting a standard RSJ, separating the pieces to re-align, then welding back together along the '''[[Neutral Axis]]'''.		In a [http://en.wikipedia.org/wiki/Rolled_Steel_Joist '''Castellated Beam'''], these are created by cutting a standard RSJ, separating the pieces to re-align, then welding back together along the '''[[Neutral Axis]]'''.

Line 38:		Line 38:


	[[File:CellularBeam.png\|200px\|right]]		[[File:CellularBeam.png\|200px\|right\|Cellular Beam]]
	A [http://en.wikipedia.org/wiki/Rolled_Steel_Joist '''Cellular Beam'''] is the modern version of the traditional "'castellated'" beam and results in a beam approximately 40–60% deeper than the original RSJ.		A [http://en.wikipedia.org/wiki/Rolled_Steel_Joist '''Cellular Beam'''] is the modern version of the traditional "'castellated'" beam and results in a beam approximately 40–60% deeper than the original RSJ.
	----		----
Line 45:		Line 45:
	</span>		</span>
	----		----
	[[File:Cleaving.jpg\|200px\|right]]		[[File:Cleaving.jpg\|200px\|right\|Cleaving a 'green' tree trunk using axe and wedges\|link=http://en.wikipedia.org/wiki/Cleaving_axe]]
	In contrast to modern practice, if you look inside a Medieval [http://en.wikipedia.org/wiki/Timber_framing '''timber-framed'''] house, such as the [http://en.wikipedia.org/wiki/Merchant_Adventurers%27_Hall '''Merchant Adventurers' Hall'''] in York for example, you will notice that roof and floor beams are often wider than they are deep.		In contrast to modern practice, if you look inside a Medieval [http://en.wikipedia.org/wiki/Timber_framing '''timber-framed'''] house, such as the [http://en.wikipedia.org/wiki/Merchant_Adventurers%27_Hall '''Merchant Adventurers' Hall'''] in York for example, you will notice that roof and floor beams are often wider than they are deep.

DT Online at 14:31, 18 December 2015

2015-12-18T14:31:59Z

← Older revision		Revision as of 14:31, 18 December 2015
Line 3:		Line 3:

	[[File:TestingPaperBeam2.png\|400px\|right]]		[[File:TestingPaperBeam2.png\|400px\|right]]
	Place two wooden blocks or similar supports 250mm apart then design a beam bridge to span the gap between them using A4 paper or thin card. Try different designs and test each one by loading it until it fails.		Place two wooden blocks or similar supports 250mm apart then design a beam bridge to span the gap between them using '''[[Paper and Card\|A4 paper]]''' or thin card. Try different designs and test each one by loading it until it fails.

DT Online: Created article

2015-12-18T14:08:09Z

Created article

New page

The effectiveness of a material for bridge building depends on the way it is used. Paper or thin card might not appear to be able to support much load but it is possible to greatly increase its strength by manipulating its shape.

[[File:TestingPaperBeam2.png|400px|right]]
Place two wooden blocks or similar supports 250mm apart then design a beam bridge to span the gap between them using A4 paper or thin card. Try different designs and test each one by loading it until it fails.

You can either add small weights to the top centre of the beam or suspend a paper cup or similar underneath. In either case you may wish to place a small section (say, 50mm square) of thicker card in the centre of the beam to spread the load a little.

Make a sketch of each design and record the results:

*how much load did it take?
*how wide was your beam?
*how deep was your beam?
*what types of traffic or services could pass over your beam?

. . . or even through your beam . . . the [http://en.wikipedia.org/wiki/Britannia_Bridge '''Britannia Bridge'''] across the '''Menai Strait''' was originally designed and built by [http://en.wikipedia.org/wiki/Robert_Stephenson '''Robert Stephenson'''] as a tubular bridge of wrought iron rectangular box-section spans for carrying rail traffic inside but had to be rebuilt following a fire in 1970.
[[File:LoadedBeams2.png|800px|bottom]]

*were some shapes stronger than others?
*was it the widest beams that were strongest or the deepest?

You will notice a difference if you try bending a ruler first on its side and then on edge. The steel girders or [http://en.wikipedia.org/wiki/Rolled_Steel_Joist '''joists'''] seen in building construction are often made in an 'I' section which is taller than it is wide. The narrow 'flanges' at top and bottom are there mainly to stop the beam buckling and twisting under load - and to provide a flat supporting surface.

Lightweight steel joists have holes along the centre, or '''[[Neutral Axis]]''', of the vertical web. You may also see these used in the [http://en.wikipedia.org/wiki/Chassis '''chassis'''] of trucks for example.

[[File:CastellatedBeam.png|300px|right]]
In a [http://en.wikipedia.org/wiki/Rolled_Steel_Joist '''Castellated Beam'''], these are created by cutting a standard RSJ, separating the pieces to re-align, then welding back together along the '''[[Neutral Axis]]'''.

This produces a lightweight beam and also increases the depth. All holes are along the centre of the web where there is least stress and the weld is along the '''[[Neutral Axis]]''', where there is little or no stress.

[[File:CellularBeam.png|200px|right]]
A [http://en.wikipedia.org/wiki/Rolled_Steel_Joist '''Cellular Beam'''] is the modern version of the traditional "'castellated'" beam and results in a beam approximately 40–60% deeper than the original RSJ.
----
<span style="color: green">'''Note:'''
If beams or joists have to be drilled to accept pipes or wiring etc., it is best to pass them close to the Neutral Axis to avoiding weakening the beam
</span>
----
[[File:Cleaving.jpg|200px|right]]
In contrast to modern practice, if you look inside a Medieval [http://en.wikipedia.org/wiki/Timber_framing '''timber-framed'''] house, such as the [http://en.wikipedia.org/wiki/Merchant_Adventurers%27_Hall '''Merchant Adventurers' Hall'''] in York for example, you will notice that roof and floor beams are often wider than they are deep.

This arises from the need to make things out of logs and tree trunks, without modern high-tech saws to cut sections from the starting material stock. A freshly felled ''''green'''' log is [http://en.wikipedia.org/wiki/Cleaving_axe ''''cleaved''''] down its centre using axes and wedges. The resulting half-round section is squared off using '''[[Planes#Traditional_Shaping_Tools|axes]]''', '''[[Planes#Traditional_Shaping_Tools|adzes]]''' and '''[[Planes#Traditional_Shaping_Tools|draw knives]]''' but the original central 'cleaved' surface provides a good flat surface on which to fix roofs and floors.

The result is a very heavy and over-sized beam - but trees at that time were plentiful!

[[Category:Bridges]]
[[Category:Beams]]
[[Category:Structures Tasks]]