Re: Units of measurement?

From: Don Slusarczyk <don5490_at_sbcglobal.net>
Date: Mon, 13 Mar 2006 01:45:28 -0500

> Wouldn't testing in the actual size ranges we deal with be more accurate?
> After all, the material is extremely variable, even 1-inch widths, and the
> B-E Beams theory excludes anisotropic materials as well as buckling
> for this
> reason.

The reason I chose 1" widths was to bulk sort the wood. I was on the
hunt for unbraced F1D spars at the time. They were about .115 x .035 at
the root so I would test 1/8" sheet. 1" was the width of my steel ruler.
Smaller strips are better to test, but then the smaller they get the
more you have to test! if you really want to make your self crazy, see
how the buckle load varies if you round the end of the sticks being
tested. The end conditions are critical in the buckling calculations and
a source of varience as well as how vertical you apply the force etc. I
tried to make a fixture to hold the beam vertial and then apply the load
with weights, and even end fittingfor the stick to plug into to ensure
the free pivoting end conditions, it just got too complicated and was
turning into a huge project. As my coworker always says, "The more you
dig into the [4 letter slang word for excrement starting with 's'], the
stinkier it gets." Based on what you are reading, you are deep into the
stink :)

Don
Received on Sun Mar 12 2006 - 22:47:33 CET