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

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

>From: clnoble@email.arizona.edu

>A quick question.  When you guys calculate the compression and tension
of >these
>poles using Young's Modulus and the cross sectional area, do you
account >for
>the tube being hollow?  

I account for the hollow cross section.  It has an impact on behavior,
so it needs to be modeled/represented properly in the math.

>I know that the equation can be used to figure out
>compression and tension on a solid item, but I didn't know it could be
used >on
>a hollow one.  

Yes, it can work in various cases...as long as you calculate the cross
section area.

>Do you just use a different value for Young's Modulus if it is
>hollow, or are you just using the modulus for aluminum?  Or is
everything >the
>same.

Young's modulus depends on material.  That's different/independent of
cross section area.  You also need to take into account the length of
the truss tubes, and the loads that the truss will bear.

 
Tom Krajci
Tashkent, Uzbekistan


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