She also flies a Pulsar.
Sonja Englert Engineering
- Thread starter BJC
- Start date
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Map
Active Member
Hi Guys,
Thanks for all the nice things you wrote about me. I'm on the forum now as Map.
Sonja
Thanks for all the nice things you wrote about me. I'm on the forum now as Map.
Sonja
jedi
Well-Known Member
Welcome Sonja.
Glad that you are here.
Can we get a quick introduction including current projects and interests.
Any pet projects?
Glad that you are here.
Can we get a quick introduction including current projects and interests.
Any pet projects?
Welcome Sonja!
Map
Active Member
I am always making small improvements to my planes, and am involved in several customers projects. One of them, the Nighthawk prototype, made its first flight 2 days ago. See my web site on the "News" and "Project" page for updates.
Map
Active Member
The way I build my molds did not allow vacuum bagging, so no core possible.
If core is used, only half the plies are on the outside, so impact damage or dents are more likely as it is on the Pulsar wing with only one ply as outer skin, not good.
If all plies are on the outside in the wing skin, the torsional stiffness is greater than that of a sandwich skin.
If core is used, only half the plies are on the outside, so impact damage or dents are more likely as it is on the Pulsar wing with only one ply as outer skin, not good.
If all plies are on the outside in the wing skin, the torsional stiffness is greater than that of a sandwich skin.
Thanks. We have this as turning point on all our discussion, but in opposite result - single skin will buckle due torsional load if not divided into many small shear cells..
And if for airloads you are fine with 10oz cf with ribs/stiffener each 6-8" - it will buckle under any bigger torsional load.
Could you provide your wing skin data oz of cf and rib/stiffener spacing ?
Map
Active Member
Typical rib spacing is 1.5 ft with 3 stiffeners in between. No buckling to limit load found.
Is the single skin shrinking between the stiffeners at all, like plywood?
Tom Nalevanko
Well-Known Member
Sonja’s videos should be required watching before any newbie questions are allowed. Well maybe?
Best,
Tom
Best,
Tom
- Joined
- Apr 22, 2020
- Messages
- 5
Back in the mid 70s, my brother & I had a composite biz. We got pretty good at mold making. That being said, I recently discovered 6 videos, made by the Arnold company, designer/creator of the record breaking AR5, that I would consider the 'Holy Grail' of perfection. His tutorial style videos are the most complete I've ever seen & would highly recommend for anyone doing composite construction, or anyone who knows how to do do it & wants to pick up some new tricks. I'm sure Sonja's work is on his level and her engineering is excellent. I'll add on link & bet if you watch one, you'll want to watch all of them. These videos apply to all forms of composite construction
Map
Active Member
I am a bit reluctant to answer this one because some may take this as an incentive to use the same ply schedule for their airplane.
Caro's wing skin layup is applicable to only this plane and its loads.
I have 2-4 plies at 45 deg of 5.7 oz/sqyd carbon in the wing skins. It varies spanwise and chordwise.
It does not sag between ribs and stiffeners and has maintained its contour well in the >5 years since I built it.
Thank you. No, i am looking for freebie up here. I did done some fea runs, to find how good/bad is single skin compared to foamed one. Here are some examples :
Not-so-solid massive core wings: Lightening the core foam
Does anyone have an analytical method and coefficients for curved plates under pressure so that we might validate Stanislavz's FEA work? Billski Is it not just a pressure vessel between the ribs? So basically hoops stress. The tangential hoop stress would be q*r/t where q is pressure and r is...
www.homebuiltairplanes.com
Not-so-solid massive core wings: Lightening the core foam
After all that, lets remember that a really well done square foot of bond line made from slightly wet micro weighs about 1/8 pound. Thanks for this info. I got more like 1/6 of pound per sq foot in other sources (about 800 grams per sq metre) Would you compare fullfoam wing to Cri-cri like...
www.homebuiltairplanes.com
Trace based simplified composite analysis. Opinions?
Ran across this recently and it looks like it might help those of us that are weak in the math needed for traditional composite analysis. Being one of those souls afflicted with apprehension at the mention of tensors and such this obviously interested me. Would any of those HBA members that...
www.homebuiltairplanes.com
and there are more live examples like Strojnik S2.. + some EU which are using single skin with pvc foam ribs..
