Re: ATM 2 Piece Poles - and how trusses really work

["Tom Krajci" <tkrajci@san.osd.mil>]

>From: "Jim Miller" <jtmiller2@comcast.net>

>how would an atm actually practically measure the compression or
extension
>of an aluminum pole in the range of forces involved in a typical atm
>telescope?

This would require a bit more in the way of jigs and use of
resources...but...

Make a truss (only two elements needed) out of one-piece tubes.  Measure
deflection of the truss under various loads such as 1, 2, 10 pounds with
a dial gauge.

Make a similar truss (only two elements needed) out of two-piece tubes.
Measure deflection of the truss under various loads such as 1, 2, 10
pounds with a dial gauge.

The only difference will be your connectors in the two-piece truss tubes
between your first and second tests.

That will let you know if your connectors spoil your truss performance.

The rest of the truss (material, cross section area, length, etc.) is
simple enough to model with simple math.  (Assuming you don't mess up
the truss with bad fabrication/implementation.)

But with this test information...you can work the math backwards to
figure out how much the truss tubes extended and compressed under
'typical' ATM loads.

Does this sound workable?

I hope this helps.

Tom Krajci
Tashkent, Uzbekistan


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