Structural elements for nanofactories - Revision history

Apm: /* Related */ added link to Static rebar profile force circuit

2017-01-31T11:46:25Z

Related: added link to Static rebar profile force circuit

← Older revision		Revision as of 13:46, 31 January 2017
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	* [[connection method]]		* [[connection method]]
			* [[Static rebar profile force circuit]]
	* [[Diamondoid molecular element]]s here also called crystolecules		* [[Diamondoid molecular element]]s here also called crystolecules

Apm: /* Sparse space trusses and tensegrity structures */ more verbose and clear

2016-07-23T12:50:10Z

Sparse space trusses and tensegrity structures: more verbose and clear

← Older revision		Revision as of 14:50, 23 July 2016
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	= Sparse space trusses and tensegrity structures =		= Sparse space trusses and tensegrity structures =

	In contrast to a space frame a space truss only takes axial forces in the nodes. No torsion moments bending moments and shearing forces.		In contrast to a space frame a space truss only takes axial forces in the nodes.
			No torsion moments bending moments and shearing forces occur at the truss nodes.

	Structures that have no degrees of freedom even when all vertices do not take any momenta (stiff space trusses) are of special interest.		Structures that have no degrees of freedom even when all vertices do not take any momenta (stiff space trusses) are of special interest.

Apm: tensegrity as subpoint

2016-07-23T12:49:14Z

tensegrity as subpoint

← Older revision		Revision as of 14:49, 23 July 2016
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	This is especially useful for advanced atomically precise products on the high performance end of the spectrum.		This is especially useful for advanced atomically precise products on the high performance end of the spectrum.

	= ~~Space~~ trusses ~~& space frames~~ =		= Sparse space trusses and tensegrity structures =

	In contrast to a space frame a space truss only takes axial forces in the nodes. No torsion moments bending moments and shearing forces.		In contrast to a space frame a space truss only takes axial forces in the nodes. No torsion moments bending moments and shearing forces.
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	Normally a less over-restrained fractal truss structure is preferrable.		Normally a less over-restrained fractal truss structure is preferrable.

	= Tensegrity =		== Tensegrity ==

	Non-redundant tensegrity base units are single point failure - if one element breaks the whole structure collapses.		Non-redundant tensegrity base units are single point failure - if one element breaks the whole structure collapses.

Apm: added section on tensioning of dense 2D ad 3D structures

2016-07-23T12:45:05Z

added section on tensioning of dense 2D ad 3D structures

← Older revision		Revision as of 14:45, 23 July 2016
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	Shape locking and spanning drive chains is an other issue (machine element).		Shape locking and spanning drive chains is an other issue (machine element).

			= Dense 2D-slabs and 3D-housing-blocks =

			Profile segments can be shaped such that when they are spanned in one axis they will pull together blocks in one or two other axes.
			This way one can fasten a huge block of very many quasi loose parts (held together only by VdW force) by only threading through tensioning chains in a single direction. Note that the pacts can not only be enclosed in the directions normal to the spanning direction (which obviously is easy) by they can also be stiffly spanned together in these directions.
			This is especially useful for advanced atomically precise products on the high performance end of the spectrum.

	= Space trusses & space frames =		= Space trusses & space frames =

Apm: all headlines one level up

2016-07-23T12:35:25Z

all headlines one level up

← Older revision		Revision as of 14:35, 23 July 2016
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	== Shape-lock-chain-core-reinforcement ==		= Shape-lock-chain-core-reinforcement =

	=== Problem ===		== Problem ==

	A main goal for structural elements is to make them from reusable standard pieces.		A main goal for structural elements is to make them from reusable standard pieces.
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	Clipping connections (not "noisily" connected to save energy) may be a bit sturdier but also increase complexity and size of the parts and thus potentially make them less reusable.		Clipping connections (not "noisily" connected to save energy) may be a bit sturdier but also increase complexity and size of the parts and thus potentially make them less reusable.

	=== Solution ===		== Solution ==

	The solution is to use shape locking as the [[connection method\|means for connection]].		The solution is to use shape locking as the [[connection method\|means for connection]].
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	One possibility would be a simple screw driven by a worm-gear for high mechanical gain. The worm gear needs to be strongly spring locked. In this special design the chain should be non-circular such that it can locally take on the torsional load introduced by the screw.		One possibility would be a simple screw driven by a worm-gear for high mechanical gain. The worm gear needs to be strongly spring locked. In this special design the chain should be non-circular such that it can locally take on the torsional load introduced by the screw.

	=== Reusability ===		== Reusability ==

	Without ''shape-lock-chain-core-reinforcement'' one needs many many truss-elements types of a very fine grained length spectrum.		Without ''shape-lock-chain-core-reinforcement'' one needs many many truss-elements types of a very fine grained length spectrum.
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	Shape locking and spanning drive chains is an other issue (machine element).		Shape locking and spanning drive chains is an other issue (machine element).

	== Space trusses & space frames ==		= Space trusses & space frames =

	In contrast to a space frame a space truss only takes axial forces in the nodes. No torsion moments bending moments and shearing forces.		In contrast to a space frame a space truss only takes axial forces in the nodes. No torsion moments bending moments and shearing forces.
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	* {{todo\|What are further highly symmetric stiff deltahedron based infinitely tessellatable truss structures?}}		* {{todo\|What are further highly symmetric stiff deltahedron based infinitely tessellatable truss structures?}}

	=== Truss nodes ===		== Truss nodes ==

	Nodes of a space truss must not put any moments or forces on the connected members.		Nodes of a space truss must not put any moments or forces on the connected members.
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	Normally a less over-restrained fractal truss structure is preferrable.		Normally a less over-restrained fractal truss structure is preferrable.

	== Tensegrity ==		= Tensegrity =

	Non-redundant tensegrity base units are single point failure - if one element breaks the whole structure collapses.		Non-redundant tensegrity base units are single point failure - if one element breaks the whole structure collapses.
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	There are hollow spiral n-gonal prismatic structures that may be suitable as frames.		There are hollow spiral n-gonal prismatic structures that may be suitable as frames.

	== Related ==		= Related =

	* [[connection method]]		* [[connection method]]
	* [[Diamondoid molecular element]]s here also called crystolecules		* [[Diamondoid molecular element]]s here also called crystolecules

	== external links ==		= external links =

	* https://en.wikipedia.org/wiki/Deltahedron		* https://en.wikipedia.org/wiki/Deltahedron
	* soft mode and self stress mode in crystal lattice https://www.youtube.com/watch?v=2ctvLT-b57M		* soft mode and self stress mode in crystal lattice https://www.youtube.com/watch?v=2ctvLT-b57M
	* Tensegrity modules for pedestrian bridges https://riunet.upv.es/bitstream/handle/10251/7275/PAP_RHODE_2221.pdf <br> by Landolf RHODE-BARBARIGOS, Nizar BEL HADJ ALI, René MOTRO and Ian F.C. SMITH		* Tensegrity modules for pedestrian bridges https://riunet.upv.es/bitstream/handle/10251/7275/PAP_RHODE_2221.pdf <br> by Landolf RHODE-BARBARIGOS, Nizar BEL HADJ ALI, René MOTRO and Ian F.C. SMITH

Apm: /* Truss Nodes */

2016-07-23T12:31:46Z

Truss Nodes

← Older revision		Revision as of 14:31, 23 July 2016
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	* {{todo\|What are further highly symmetric stiff deltahedron based infinitely tessellatable truss structures?}}		* {{todo\|What are further highly symmetric stiff deltahedron based infinitely tessellatable truss structures?}}

	=== Truss ~~Nodes~~ ===		=== Truss nodes ===

	Nodes of a space truss must not put any moments or forces on the connected members.		Nodes of a space truss must not put any moments or forces on the connected members.

Apm: truss nodes headline one level deeper

2016-07-23T12:31:20Z

truss nodes headline one level deeper

← Older revision		Revision as of 14:31, 23 July 2016
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	* {{todo\|What are further highly symmetric stiff deltahedron based infinitely tessellatable truss structures?}}		* {{todo\|What are further highly symmetric stiff deltahedron based infinitely tessellatable truss structures?}}

	== Truss Nodes ==		=== Truss Nodes ===

	Nodes of a space truss must not put any moments or forces on the connected members.		Nodes of a space truss must not put any moments or forces on the connected members.

Apm: /* Space trusses & space frames */ added details on truss nodes

2016-07-23T12:30:40Z

Space trusses & space frames: added details on truss nodes

← Older revision		Revision as of 14:30, 23 July 2016
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	In both cases octahedra need to be added.		In both cases octahedra need to be added.

	* stiff ~~Icosahedra~~ can incompletely but ~~ininitely tesselate~~ space (leaving ok gaps) - they form rhombic dodecahedral super-structures. Octahedra can be interleaved.		* stiff icosahedra can incompletely but infinitely tessellate space (leaving ok gaps) - they form rhombic dodecahedral super-structures. Octahedra can be interleaved.

	* {{todo\|What are further highly symmetric stiff deltahedron based infinitely ~~tesselatable~~ truss structures?}}		* {{todo\|What are further highly symmetric stiff deltahedron based infinitely tessellatable truss structures?}}

			== Truss Nodes ==

			Nodes of a space truss must not put any moments or forces on the connected members.
			Thus when the members rotate their virtual extension lines must always run through the nodes center point.
			Simple naive off center hinges do not provide this functionality.
			A proper truss nodes thus needs to be designed a little more elaborately such to allow two layers of different radius cylindrical sliding around the common node rotation point oriented normal to each other (combined this is spherical sliding).

			When tensioning a segmented truss member the connections to the node points should be included in the ''force cicuit'' such that the node menḿber connections do not introduce uncontrolled lash.

			A fully interlinked octett truss has twelve truss members pointing to every node (along the 110 directions) this can become quite crowded.
			Normally a less over-restrained fractal truss structure is preferrable.

	== Tensegrity ==		== Tensegrity ==

Apm: /* Trussworks & space frames */ explaining difference between trusses and frames + icosahedron space tesselation mentioned

2016-07-23T11:54:01Z

Trussworks & space frames: explaining difference between trusses and frames + icosahedron space tesselation mentioned

← Older revision		Revision as of 13:54, 23 July 2016
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	Shape locking and spanning drive chains is an other issue (machine element).		Shape locking and spanning drive chains is an other issue (machine element).

	== ~~Trussworks~~ & space frames ==		== Space trusses & space frames ==

			In contrast to a space frame a space truss only takes axial forces in the nodes. No torsion moments bending moments and shearing forces.

			Structures that have no degrees of freedom even when all vertices do not take any momenta (stiff space trusses) are of special interest.

	~~Structures that have no degrees of freedom even when all vertices do not take any momenta are of special interest.~~
	In this group falls the set of deltahedra (all faces are equilateral triangles).		In this group falls the set of deltahedra (all faces are equilateral triangles).
	They can be intuitively explored by the usage of the popular geomag construction toy.		They can be intuitively explored by the usage of the popular geomag construction toy.
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	* Tetraherda cannot be used to fill space. This is what happens if you try: [https://commons.wikimedia.org/wiki/File:Quadaugmented_tetrahedron.png (link to wikimedia commons image)]		* Tetraherda cannot be used to fill space. This is what happens if you try: [https://commons.wikimedia.org/wiki/File:Quadaugmented_tetrahedron.png (link to wikimedia commons image)]
	In both cases octahedra need to be added.		In both cases octahedra need to be added.

			* stiff Icosahedra can incompletely but ininitely tesselate space (leaving ok gaps) - they form rhombic dodecahedral super-structures. Octahedra can be interleaved.

			* {{todo\|What are further highly symmetric stiff deltahedron based infinitely tesselatable truss structures?}}

	== Tensegrity ==		== Tensegrity ==

Apm: improved notes on recyclability

2016-07-23T07:33:10Z

improved notes on recyclability

← Older revision		Revision as of 09:33, 23 July 2016
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	One possibility would be a simple screw driven by a worm-gear for high mechanical gain. The worm gear needs to be strongly spring locked. In this special design the chain should be non-circular such that it can locally take on the torsional load introduced by the screw.		One possibility would be a simple screw driven by a worm-gear for high mechanical gain. The worm gear needs to be strongly spring locked. In this special design the chain should be non-circular such that it can locally take on the torsional load introduced by the screw.

	~~When ''shape-lock-chain-core-reinforcement'' is used a lot of small passivated [[crystolecules]] can be made reusable. (See: [[Recycling]])~~		=== Reusability ===

			Without ''shape-lock-chain-core-reinforcement'' one needs many many truss-elements types of a very fine grained length spectrum.
			If an old macroscopic product is to be recycled in a new one where most of the truss lengths don't match the parts can't be reused.

			When ''shape-lock-chain-core-reinforcement'' is used instead there is no longer a need to have a variety of unwieldy truss elements.
			Instead one only has a lot of small passivated [[crystolecules]]. And those are much more likely to be reusable in a new very different makro product. (See: [[Recycling]])

			Also long thin high aspect ratio truss elements may be a bit harder to handle robotically than small compact ones in a narrow size range.