Rebar chain tensioning

(wiki-TODO: Add illustrative images of tent-poles and concrete rebar and 3D printed example.)
Partly abstract concept page.

Motivation

This principle is about enabling quick recomposability of higly reliable assemblies. To that end:

• Avoid the need for pre-production of new base-part for slightly different geometry situations.
  Use sets of standardized sets (generally of smallish-aspect-ratio).
• Avoid the need for many high actuation effort tensionig elements. I.e. batch the process.
  Here "effort" refers to required: energy, peak power, time
  Avoid tensioning needed at every single interface between parts.
  Drag out the need for a high effort tensioning action to only after the pre-assembly of a larger number of parts.
  

Side-note: Constraint to mall aspect ration parts is related to self replication capability.
(parts of such nature that they can be handled by one size of robot made form these same parts).
This goes beyond the rebar chain tensioning core principle though.

Why not just clip the parts together instead?

Yes, clip connectors orthogonal to the load
combined with design principle of passive pretension
can likely be a less involved alternative in terms of
complexity of shapes of parts, number of parts, and system operation.

But these advantages comes as a trade-off. One gets several downsides:

• More constraints on loading directions
• More constraints in the mechanical behavior of the connections (especially in nanoscale atomistically granular systems).
• Possible a bit more actuation effort (energy, peak power, time) for each connection.
• Pretension is likely more localized. => Possibly lower limits on maximal strength.

Doesn't the actuation effort just add up anyway and thus need to be processed anyway?

The assembly is serial for one still only needs to tension up to the same force.
There is core-chain flex though which increases the amount of energy that is needed a bit (linearly growing).
High power actions being batch processable is likely an advantage.

Employed sub-principles

Several sub principles are employed in order to drag out this eventually unavoidable need.

• form closure for the core chain in the hull segments
• weak reversible bonding in pre-assembly (clip connectors / vdW force for nanoscale systems)
• positive locking of the final common tensioning element to make it extremely reliable against accidental partial of full detensioning
• self centering between the hull segments to get nicely define coordinates when attaching stuff to structures formed by the hullsegmenst

Related

• Scale agnostic mechanical design principles

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• ReChain frame systems & ReChain index

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• ReChain core chain & ReChain hull segment
• ReChain hull segment stack

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• ReChain fir tree core chain segments
• ReChain length adjustment hull segment
• ReChain tubular core chains & ReChain cylindrical hull segment
• ReChain naked core chain

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• ReChain tensioner
• ReChain tension redirection method

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• Form closure

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• Clip connector & Design principle of passive pretension
• ReChain assembly helper clip locks
• ReChain clip locks & ReChain clips
• ReChain snap clip
• ReChain VdW emulation clip locks