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Sonja Englert Engineering

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rbarnes

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Hi Guys,

Thanks for all the nice things you wrote about me. I'm on the forum now as Map.
Sonja
Keep the vids coming on YouTube Sonja.
Great stuff and VERY helpful as I start my the conceptual layout on my project.
 

plncraze

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Show the folks here a drawing of the Mooney wing that you designed. That was cool!
 

stanislavz

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Hi Guys,

Thanks for all the nice things you wrote about me. I'm on the forum now as Map.
Sonja
Glad to have such person alive on HBA.

I was referring Caro motorglider as an example of non-standart thinking - single skin with many reinforcements vs standard sandwitch construction..

Could you make a short explanation, why it was done in this way ?

Thank you !
 

Map

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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.
 

stanislavz

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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 ?
 

Shorttimer

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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

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And skin thickness ?
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.
 

stanislavz

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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 :




and there are more live examples like Strojnik S2.. + some EU which are using single skin with pvc foam ribs..
 
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