I an amateur rocketeer working on a experimental two stage rocket. Majority of the parts on the rocket is made from Baltic Birch Plywood. The fins are made from Baltic Birch Plywood; the upper stage fins are 3/8 inch thick and booster stage are 1/2 inch thick. I need to find the modulus of elasticity of the upper and booster stage fins. What is the formula for finding modulus of elasticity of Baltic Birch Plywood? Thank you from "We're Not Engineers"
What is the formula for modulus of elasticity for 1/2 inch baltic birch plywood.
Aug 11, 2015
8 Replies
Maybe ask the guy in the lumber isle wearing the vest that says "May I Help You"?
"We're Not Engineers" wrote on 8/11/2015 :
I have no idea, but I did find this:
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They seem to divide it into classes - see table three.
No formula is mentioned though, it seems they do actual measurements.
You should be able to google it up. One abstract said it is higher than fiber glass.
On Wed, 12 Aug 2015 01:44:02 +0000, "We're Not Engineers" wrote in
You might try
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by contacting the "WebMaster" at the bottom of the page.
DAGS for "baltic birch mechanical properties"
Another location to search is the US Forest Products Laboratory site
On Wed, 12 Aug 2015 07:31:44 -0500, CRNG wrote in
I also passed your question to a friend who has been doing "model" (some 6' or 8' long) rockets for many years. Here's his reply
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Here is a link that gives the modulus for several types of birch though not Baltic. These numbers are not very meaningful except for the comparison of different types of wood. If I couldn't find the value for Baltic I would use the value for Alaskan birch.
Ron
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And, of course, it being ply it's highly asymmetric depending on orientation and will also be dependent on the particular fabrication of just how many plies are in the specific manufacturer's lot. 3/8 (9 mm) by the Russian GOST spec contains 7, while 12 mm is 9 but I've seen cheap stuff imported from the other side of the globe purported to be "Baltic birch" at the BORG that isn't...it has solid hardwood plies but they've cut the number of plies down. That'll be quite a bit less stiff than "the right stuff" if happened to find some of that and presumed like most folks what it's called is good enough.
replying to Will Robinson, The great cornholio wrote: That guy is not going to know what modulus of elasticity is, and neither do you.
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