Jane-Doh

A very simple concept is spread. Distribution of stress allows for lower weight, crucial in the aviation application. At some point, the adoration of complexity for its own sake must be sacrificed to make money. The military application of wildly expensive formats is crazy apparent.

Variable geometry, "Stealth", "Flying Wing", too many more to bring up. Skeletal frames covered in skin go back to the first of the Chordata, animals with "Bones".

Almost Anything is possible, and being possible, welcoming of discussion. The most efficient Space vehicle currently is made of CFRP, has no bones, and burns Rubber in "pops" that make it sound like a "Buzz" engine. Sometimes I think Rutan does what he does just to make fun of the dinosaurs who think with old Brains, and use technology that was old when Mother Nature had her "A-Hahs".

The Helical Frames in those old bombers were copies of the "Chinese Finger", not some marvel of Human Intellectual innovation.

How about a vehicle whose body work doubles as its energy tankage??

Li-Poly/ Plastic as Electrode, and formed into Fender, and coachwork.

The newest Airframe is virtually indistinguishable from early Post WW2 bombers.

The secret to making money is not to make things complex, but to make them simply.

Having no understanding of why Geodesics interest you so, I may be missing your point here. Sorry if that is the case.

I think Jane may be wishing us to refer to geodesic carbon C60 molecules, known as Buckminster Fullerene or Bucky:mad:s. Well, I wasn't going to say it in front of a lady, was I?

Nah she wants to suss us men out. Wants to know what kinda figures we prfr. I prfr size 7 shoes and 31 inseam myself.

Alas all too true, though I am honour bound not to reveal the content of pms that may have passed between herself and myself. You might wish to ask her to look at test pilots and express opinions.

WOW MIKE!

You saying she is a real life version of the lady on Top Gun!

Adds up...thanks for the heads up! :cool:

They did assemble one in less than 24hrs though....

Wellington in a Day

All they did was "slot the frames together like Meccano". Just final assembly. They didn't make all the components and assemble the frames.

Nice shades, fox-hunter. :ok:

You might be slightly under-estimating those Vickers workers, mike-wsm! :)
Fair enough - each assembly section had its seasoned experts but it was still quite an achievement to put a large aircraft together in 24 hours, especially considering the fabric doping procedure.A lot of flying/engine control & undercarriage rigging involved there as well.
I've done a bit of that on older aircraft - respect to those men and women :D

stevef

I was quoting directly from the reference cited by TURIN.

My original statement was "The Wellington took a lot of (wo)man-hours to build" and by implication I was comparing it with other contemporary aircraft.

bearfoil

I just found geodesic airframes fascinating because they were very sturdy and the use of the vanished after WW2.

To be clear the geodetic airframe was helical in nature, not using angled frames (at first my impression was that each frame was simply angled forward -- take a hula-hoop, hold it in front of you and tilt it forward) one angled forward and backward to intersect?

Regardless, the geodesic design seems to have some overlaps with trusses (as there are a lot of intersections and produce a lot of quadrilateral and triangular shapes, and the image inside the Wellington did seem to have a series of truss-structures in them).

I know modern composites are far more effective than this design, and I'm not actually a proponent of excessive complexity (my general attitude is: If you're given the choice between simplicity and complexity; use simplicity unless complexity is needed to accomplish the task).


DERG

I wouldn't say that, but I do have some skill with remembering figures and such.

Hi Jane

The problem with geodesic architecture is its rapid loss of strength in planar shapes.

Without proper materials, Geodesic looks wonderful, it has lightweight, and superior strength. No need for all that work when up jumps polymer. Even some time spent on the English wheel will give Aluminum sheet practical Strength/Weight. In every cube of Granite lives a David. Leonardo is not exactly on speed dial on the shop floor, however.

Inside the shell of a Tortoise are what look like Vestigial "Ribs". They are not ribs, though, they are frames, giving Mr. Slow's carapace some "Trusswork". The finest architecture is found in the Natural World. Human beings can get so full of themselves when the focus is narrow. Pride goeth before the Fall, eh??

I'd never thought of a tortoise as being semi-monocoque before.

G

Entomology trumps Boffinology??

Insecta have completely monocoque design. Exoskeleton. Body/Exo, Wing/Skeletal

In the scheme of things, Boeing and Bus are basically just monstrous honeybees.

Engineer, get thee not overprecious!!

Robyn
Oh yes..indeed.

airships
 

Back to airships. The lifting gas must be lighter than air. The ultimate lifting gas would be none at all, a vacuum. But atmospheric pressure would crumple this envelope. But if it was a geodesic shape with tension bonds attached to enough nodes to prevent crumpling of the inner bag, could the outer ends be fastened to another geodesic frame such that all it members wre in compression?

The problem with a vacuum is that it takes such an incredibly long time to make. It's quite easy to pump out the first bit, but the less air there is in there, the longer you have to wait for the molecules to whizz around enough to reach your outlet and get pumped away. It is beneficial to start heating the interior as the pressure drops but there are limits to how much heat you can apply and still retain structural integrity.

bearfoil

What kind of architecture goes well with planar shapes? From an academic standpoint is it possible to integrate a geodesic fuselage with other types of architecture in the wings?

Academically speaking, is it possible to create a geodesic frame out of polymers? :}

I never thought of it that way...


mike-wsm

You'd almost certainly need a hard-shell for this, but if you had a series of access panels, few hundred let's say all over the surface of the blimp. That way you could stick pumps in and suck out the air more rapidly than if you had one hole and one pump. You could also rig a network of porous tubes through the frame to amplify the effect, if they were sturdy enough they could provide some load bearing functions allowing you to reduce strength in other parts of the blimp to keep the weight in line. I'm not sure I'm explaining this right...

LMAO! That was the exact idea I was thinking of as I read what you were writing about the pressure dropping and the time to drain out everything increasing -- as the pressure drops increase the temperature which does increase the pressure, but because the atoms are moving faster they'd all fly out of the vessel quicker even as the pressure gets very low, and once there's nothing left you still have no pressure so you just seal everything up and then either cool it down while on the ground or just lift off and let the outside air temperature cool you down

Hi Jane

Geodesic is a method, architecture is a volume. Which brings up the best way to create a vacuum. Two discs of strong metallic construction are welded together at their shared rim. From either side, and at the center, the discs are separated, mechanically. Theoretically, there being no space between the discs at the start, the more one can separate the two, the larger the "perfect" vacuum one creates. This is the theory that propels us through the air and across the land.

But. There is no such thing as a 'vacuum'. It is an artful way of saying 'less pressure', migrating to none.

Vacuum must have a mate, existentially. We call it 'Pressure'.

A 'Geodesic' of polymer? Simples. Start with a CFRP Soccer ball, and start drilling. In mechanics, this is called 'relieving', exchanging strength for light weight. If you like, pattern your relief on the hexagon, pentagon, etc. Imagine a 'wiffle ball', then.

The beauty of polymer is that it takes so little work to attain marvels of strength and resilience. Polymer is frame and skin at one with whatever shape one wishes. In airframes, or sailboats, structure is pleasant when it has few components. A mold, some A, some B, some woven matrix, and a 'vacuum cleaner', voila, a 44 foot Marples prime for the single handed TransPac.

bearfoil

I apologize for my incorrect terminology. Regardless, what I meant was is it possible to design a tubular structure with a geodesic construction method, then where planar shapes form to shift to some other structural design method? Also is it possible to create tubular geodesic spars instead of the traditional spar configuration?

I would have never thought of a wiffle-ball that way