Wing spar design 1

[craghav]

Hey please tell me what is the basic geometry of spar? is it H section? what are the materials used? stainless steel? how to manufacture it?
what are the design consideration to be made? can we apply principles of cantilever beam?

 

[rb1957]

I section
Al alloy (7050), possbily Ti, possibly composite
NC machined
?
sure, depending on the overall wing design (cantilever or strut)

try reading Michael Niu "Airframe Structural Design"

be carefull if you're a student ... the questions are suspiciously non-professional

Quando Omni Flunkus Moritati

 

[MikeHalloran]

i used to work next to a spar milling shop,
in the days before widespread CNC use.
They just hired guys who could turn the cranks on a regular milling machine,
paid them modestly,
and fired them if they took a cut less than 1/2" deep.
The place was literally hip deep in chips at the end of the day.
The material was clearly aluminum.

Note that there are many aluminum alloys and tempers, some of which reach yield points higher than mild steel.

Stainless steel is very weak (low yield point) relative to its weight, so it's not a good material choice for large aircraft parts. Some tempers of 2024 aluminum have a higher yield point and are hundreds of times easier to machine than any stainless. That's why spar milling with >95 pct material removal was competitive (to spars folded and riveted from sheet anything) even before CNC.

I think the Russians have built complete combat airplanes (or at least complete skins) out of steel, but it wasn't stainless; regular maintenance must have included polishing and waxing; when they were parked outdoors and not maintained for a while, they rusted. That came as a surprise to our intelligence people; we had assumed the planes had titanium skins because the USSR mined its own rutile, and had a native titanium supply large enough to use for making submarines.

Mike Halloran
Pembroke Pines, FL, USA

 

[dgapilot]

Kind of depends on the airplane. Could be wood, steel tube, aluminum sheet that is flanges, aluminum sheet with extruded angles riveted on, aluminum milled, composite fiberglass, composite carbon fiber. You need to be much more specific.

 

[GrandpaDave]

rb1957... Michael Niu "Airframe Structural Design" IMHO is very difficult to follow and read.
Good old Elmer Bruhn's "Analysis and Design of Airplane Structures" is easier to read but one
need correction sheets. Check the Internet for correction sheets.
G-pa Dave old and retired and tired.

 

[rb1957]

the question made me think of my first plane book ... "Timothy's book of aircraft"

bruhn i thought would be too technical, maybe the introductory stuff ...
airplane design books, like Raymer, torenbeek, etc; heck wiki

Quando Omni Flunkus Moritati

 

[Sparweb]

I don't think a book is necessary at all.
I think a "google" search should be sufficient to answer the OP's question.
Not sure why he/she didn't try that first.



STF

 

[rb1957]

'cause some people think we'll do their searches for them ??

Quando Omni Flunkus Moritati

 

[GrandpaDave]

Yep... Start billing these folks and you could retire as a millionaire.
Then POTUS would consider you the evil rich and demand more taxes…

 

[dgapilot]

I should have started a 1-900 phone nuber long ago for all the free information I've given out over the years. I could retire now.

 

[berkshire]

dgapilot (Aeronautics)
Ya think?
B.E.