First of all I would start with the important stuff and ignore some of the details where it is possible to become bogged down. Look at the aeroplane as a whole, how large does it need to be (how much should it carry), how fast, what size of runway (and so what stall speed), visual or instrument flying, how far, what building skills do you have, what materials do you like to build with, what is your budget and so on. These are interlinked questions, it will take a while to find a compromise that answers all the questions to your satisfaction. Have you joined the local EAA chapter? Perhaps there is someone amongst the membership who can help?
Mathematics in aircraft design
- Thread starter FrankenWompus
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drgondog
Active Member
Vigilant/Mark - I agree your comments about 'deathless prose' regarding Peery. That said, IMO, understanding his material and applying it correctly is a minimum to proceed in detail stress analysis.Thanks for your insight.
Like the OP, my math skills are limited (algebra is fine, trig I can hack through, what little calculus I truly understood left me long ago). Even with this meager numerical toolset, I've found it possible to do some basic conceptual design tasks (Raymer is my hero, and there are other good sources). I'm finding that design of structures is a much tougher nut. I'm glad you found Peery to be useful, but in my opinion his prose is very obtuse. I suppose this was a common way of writing when he wrote the book (1950), and it is an engineering textbook and not targeted at a "lay" audience, but that doesn't make it easier to understand. Thankfully, it does have good drawings and some exercises (no answers). I'm sure it is a great text for aspiring engineers who have a good math foundation and who need to be exposed to a lot of different situations.
While it is quite different, I found Richard Hiscocks' "Design of Light Aircraft" to be useful and remarkably straightforward. It is clearly targeted toward amateurs, and gets right to the point. Unfortunately, it doesn't cover structural design, but appears to do a good job of explaining how to calculate loads (which is a very important first step, and a logical one after the conceptual design phase). Loaded with concrete examples of every concept, which I find to be the best way to explain things.
Regarding structures, Billski has been very generous with his time in explaining many typical calculations (see the HBA "stickies." Some "greatest hits" include Beam Theory Explained---How Spars Work, Mechanics of Composite Plates, Beams, and Bigger Structures, etc). "Stress without Tears" has been recommended by mcrae0104, so that will be the next stop in my search for a basic explanation of aircraft structures.
Thanks again,
Mark
Thanks. Peery is surely worth the slog. Since he starts each topic in a highly abstract way and eventually gets to a tangible example, sometimes it goes down easier for me if I start at the end so I can see why/if the subject is of use and so I can put the highly abstract stuff into context.
Jimstix
Well-Known Member
Note on Perry: It comes is two versions, old and new. IMHO, the older version (without the co-author) is much more useful.
drgondog
Active Member
I mentioned this once above, but a PhD in 'practical" stress analysis is imbedded in the MISC folder f the Smithsonian P-51 Mustang Collection. Both a 500 page NAA Report of the structural analysis of the P-51D-5-NA wing as well as the 70 page NAA NA-8449 Performance Analysis for the P51D-5-NA.
Vigilant - it has the questions and the excruciating detailed answers for airframe stress analysis that Peery did not supply, including applying aero loads on wing and bomb drag spanwise - to calculate bending loads - as well as tabular reduction of complex shapes to yield moments of inertria.
Vigilant - it has the questions and the excruciating detailed answers for airframe stress analysis that Peery did not supply, including applying aero loads on wing and bomb drag spanwise - to calculate bending loads - as well as tabular reduction of complex shapes to yield moments of inertria.
You made more progress than I did. The Smithsonian technical archives don't seem to be organized as I would have expected. Is much of this still on microfilm/microfiche? Can someone share a link to the index entry for the P-51 material, if not the material itself? Thanks much.
drgondog
Active Member
The Misc folder contains three reports - 2 structural and 1 Performance - total ~ 80Mb, 500+ .jpg docs. I can send vis Wetransfer to an email address. Does this site have a destination address for docs?
wktaylor
Well-Known Member
FW... short cautionary note.
Broad-based knowledge and experience is essential.
Pure math skills alone won't help You define a real-world aircraft. They transform the dream to potential-reality.
Aviation craftsmanship skills ARE ESSENTIAL... understand the 'rules' of how-to, why-to, when-to, where-to, etc. of every element of a intended assembly practices. This includes practical systems knowledge: controls, engines/powerplants, electrics, etc. This is where friends and other experts can help a lot. Make sure You receive 'wise/experienced council'.
Structural and mechanical materials, finishes, parts and essential fabrication processes are the 'stuff' that transforms the semi-real aircraft to a reality. This is where friends and other experts can help a lot. Make sure You receive 'wise/experienced council'.
Then comes the hard work and long hours of focus. AND, Always remember... You/family/friends 'pink-on-the-inside bodies' are on-the-line.
Parting thoughts...
Know the rules well, so you can break them effectively." --Dalai Lama XIV
The J3 Cub is the safest airplane in the world; it can just barely kill you. ~Max Stanley, Northrop test pilot
Some fear flutter because they do not understand it. And some fear it because they do." Theodore von Karmen
A dream doesn't become reality through magic; it takes sweat, determination, and hard work. --Colin Powell
Broad-based knowledge and experience is essential.
Pure math skills alone won't help You define a real-world aircraft. They transform the dream to potential-reality.
Aviation craftsmanship skills ARE ESSENTIAL... understand the 'rules' of how-to, why-to, when-to, where-to, etc. of every element of a intended assembly practices. This includes practical systems knowledge: controls, engines/powerplants, electrics, etc. This is where friends and other experts can help a lot. Make sure You receive 'wise/experienced council'.
Structural and mechanical materials, finishes, parts and essential fabrication processes are the 'stuff' that transforms the semi-real aircraft to a reality. This is where friends and other experts can help a lot. Make sure You receive 'wise/experienced council'.
Then comes the hard work and long hours of focus. AND, Always remember... You/family/friends 'pink-on-the-inside bodies' are on-the-line.
Parting thoughts...
Know the rules well, so you can break them effectively." --Dalai Lama XIV
The J3 Cub is the safest airplane in the world; it can just barely kill you. ~Max Stanley, Northrop test pilot
Some fear flutter because they do not understand it. And some fear it because they do." Theodore von Karmen
A dream doesn't become reality through magic; it takes sweat, determination, and hard work. --Colin Powell
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brad.walker
New Member
Can you point me to where I can find this as I'm very interested.
Also, my email address is: bwalker@musings.com if you want to email it.
Thanks for sharing this knowledge!
-brad w.
FrankenWompus
Member
- Joined
- Dec 16, 2020
- Messages
- 5
Thank you for this.
Unfortunately the closest EAA Chapter to me is a couple hours away, but I suppose it's worth reaching out all the same.
Most of my life, in most things, I've struggled with "analysis paralysis". I'm definitely aware of it, and I can see myself reading books, ordering plans, faffing about online and never actually welding a single tube. I'm working on that part of myself.
I heard something awhile ago that has helped out. "It's not about knowing everything, it's about knowing enough." In this case "enough" is enough to successfully build a safe and reliable airplane, though I expect it will be awhile before I do know "enough".... or know that I know enough.
You will never know enough. The more you know, the more you realize how little you know.
Jimstix
Well-Known Member
Old guy rule of thumb: Stress analysis is easy, loads analysis is hard.
Jim
Jim
- Joined
- Oct 27, 2009
- Messages
- 3,647
Even though the closest chapter may be far far away the closest MEMBER might be in that big shed just across the street.......
drgondog
Active Member
Brad - I prefer to upload the folder just once. If the website here doesn't permit it I will send the stuff to you. I just sent an email to Admin about uploading into Media
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The height of ignorance is when you don't know and you don't know that you don't know. So you think you know everything.
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