I think it is I who am missing something. Given equal weight, and suspended vertically from an end, the strain is equal. An engineer (amicus?) would have to input here, for stress is only a factor insofar as it is spread, yes? If I had a choice of material but was limited in mass, and was free to design the tube, I would select a composite, for intrinsic in the shape is the inclusion of geo- stringer, skin- etc. Incorporating the frame with the consolidating skin gives strength and weight saving. Strength (Stress) is always best when distributed, rather than focal??
edit. Did you see that I proposed suspending the "tube" from "both" ends, to simulate dynamic load?
And, if not for drag, perhaps a helix !!
Last edited by bearfoil; 20th March 2011 at 01:08.