[TowerTalk] Aluminum mast

[Jim Lux]

At 09:21 AM 3/15/2006, doc wrote:
>>So, to answer, for the same weight of tubing (which is how you buy it, by 
>>the pound), the tube is stronger than the rod.
>
>Unless or until the tube takes a blow which
>compromises its relatively thin (compared to
>the rod) thickness -- it is less likely to
>resist the impact thus denting and becoming
>more prone to collapse (depending on the side
>and depth of the impact area).
>
>Is that correct?

Sure, any defect causes a stress concentration.
And, any BIG dent changes the size of the tube, which changes its strength 
(because everything hangs off that radius of the member term)
It would also depend on what the failure mode is (bending or column buckling)

But, I'm sure you've all seen the demonstration where you support several 
hundred pounds on a sheet of paper on edge, rolled in a tube.