Karl,
I've uploaded a file showing the shear and moment diagram (general) for the wing. I'm not convinced the 2-splice wing is stronger (actually you would size either configuration to be strong enough), and I'm not even sure it's lighter in the end. I suspect that what is driving the Arc in that direction (though I freely admit I don't know for sure) is that they can leave the flaps rigged on the center section and they can also have separate flap and aileron AND you can get it all in a trailer that is 5 foot shorter. I don't think it is lighter and the outboard joint is a little trickier than it looks (not that it can't be done that way of course!). Take a look at my comments. It is still VERY much open for discussion! As an engineer, I can tell you without ANY hesitation that everything is a compromise and there isn't a perfect way of doing anything; however, the results will not be the same!
Kenny

--- On Tue, 3/27/12, KarlS <This email address is being protected from spambots. You need JavaScript enabled to view it.> wrote:


From: KarlS <This email address is being protected from spambots. You need JavaScript enabled to view it.>
Subject: [Carbondragonbuildersandpilots] Re: 3-piece wing calcs, thoughts
To: This email address is being protected from spambots. You need JavaScript enabled to view it.
Date: Tuesday, March 27, 2012, 7:46 AM



Good morning Russ.
Or at least I think it may be morning where you are. I am in western Pennsylvania just for an fyi.

My thoughts on the 3 piece wing are ease of build, higher strength, less weight.

The quote from Dieter Reich about getting rid of the heavy wing fittings needed for a 2 piece wing keep ringing in my head.

Much lighter fittings would be need splitting the wing in 3. Plus flap/aileron sizing.

You can not argue the Arc layout.

Kenny, would it not be significantly stronger with continuous spar across the fuselage? It seems to me it would be. Phil, did you get your calculations done. Not that you haven't been busy but.. good humor intended sir.

And Russ here is a good photo of what we can do. A 16 foot trailer is a nice compact little hangar. 16x6 should be plenty.

groups.yahoo.com/group/Carbondragonbuild...inal&start=1&dir=asc

Have a good day guys.

Karl