Tube wing spars

On Mar 18, 8:12 pm, Ernest Christley wrote:
Fred the Red Shirt wrote:



On Mar 18, 12:24 am, Ernest Christley wrote:
wrote:
Actually I'm interested also to know if any other designs besides BD
aircraft utilize wing spars that are made of aluminum tube.
So if you know of any I'd like to know what they are.
Dyke Delta uses a welded truss made 4130 tube...each section's
crossmembers were of a different size.

Ah but in terms of stress/strain, a truss is closer to
an I-beam than it is to a single tube.

Unless of course it is a very peculiar truss.



Nope. About as straightforward as they come.

http://ernest.is-a-geek.org/Delta/Pictures/Wing1.jpg

Would you believe:

http://www.ernest.isa-geek.org/Delta/Pictures/Wing1.jpg

And that wing spar looks to me to be, in terms of stress and
strain, to be truss that is a lot closer to an I-beam than to a
single tube. The top and bottom tubes are like the flanges
of an I-beam and the diagonals are like the web.

If you took out the spar, took the 'sticks' out of the ribs then
it would at least look more like a single tube. If you added
a stressed skin, then it would behave like a single tube.

And that would be peculiar.

--

FF