Difference between revisions of "Static rebar profile force circuit"

Latest revision as of 12:47, 31 January 2017

This is a compact collection of all the necessary pieces to make highly reusable structural strut elements out of multiple parts for robotic systems of all sizes.

It's basically a tensioned rebar-chain going through a stack of profile segments closing up circuit of force.

tension chain segments

The tensioned chain running through the core. Obvious design choices are:

• classical chain segments
• interdigitating U-shapes

In case of rectangular or square chains 90° Turning elements might be useful.

compression hull segments

The compressed hull segments surrounding the tension chain. The outer surface can serve many function (or none at all). Possible functions: ...

self centering alignment surfaces

To prevent undefined misalignment errors adding up in many cases it might be necessary to corrugate the contacting surfaces of the compression hull segments in such a way that when they get compressed together they self align to only one possible allowed and desired configuration.

As a side-note over-standing corrugations can be used to lock together multiple 1D tensioned rebar profile struts in parallel thereby forming 2D walls and 3D housing blocks. Locking the struts together in nonparallel fashions seems more difficult.

bending prevention widenings

Compression hull segments with minimal hull thickness suffer from low bending stiffness. When bending force is applied a high mechanical advantage pries the compression hull segments apart. To prevent this the contacting surfaces need to be widened to about the thickness of the chain in the core.

Length adjustment

There's length adjustment for:

• determining the length of the strut
• allowing proper tensioning

The parts for these two functions may or may not be the same depending on the design.

structure length adjustment segments

To choose the length of a tensioned rebar profile strut length adjustment elements are needed. Depending on the type of tensioner either the hull segments or the chain elements fulfill this function.

tension length adjustment segments

To get the sum of the lengths of the tension/compression elements to the right length for proper tensioning length adjustment elements are needed. Depending on the type of tensioner either the hull segments or the chain elements fulfill this function.

Tension to compression inversion point(s)

A specialized shear loaded part is needed at the at the passive end of the strut where the chains tension finally turns around and pushes back on the stack of profile segments.

Tensioner / Spanner

Details can be found on the main page about: Tensioning mechanism design

Mechanical gain element

Allowing easier and more fine grained and controlled spanning.

tension retainer spring

Preventing unintended release of tension through an energy barrier.

• Mandatory on the nanoscale (superlubriction, thermal motion, thread lead limit),
• Beneficial on the makroscale (loosening through vibrations and environmental factors like e.g. moisture)

unintended disassembly prevention spring

Preventing rapid unplanned disassembly. This function can be combined with the tension retainer functionality for compactness but can also be seperated out

spring energy recuperation lever

Snapping a spring emits sound waves carrying away energy. While not critical on the macroscale in efficient diamondoid nanosystems recuperating that energy might allow for faster operation since less waste heat needs to be removed.

• Beneficial on the nanoscale
• Useless on the macroscale

Related

• Structural elements for nanofactories