Re: Determining balsa stiffness

From: markdrela <drela_at_mit.edu>
Date: Sat, 14 Jan 2006 02:52:13 -0000

I just uploaded foam_stiffness2.pdf to the Files section. This shows
a method of determining the modulus (stiffness) of a material, using a
simple 3-point beam bending test. It has been used by myself and Phil
Barnes to tabulate the moduli of many different types of foams used
for RC glider wings. The same method can certainly be used for balsa,
and is in fact simpler, since the Beam Preparation steps can be
skipped. Just take the balsa sheet and go straight to the Deflection
Measurement.

The test is very quick and reliable, and uses the inside jaws of a
caliper to measure the deflection. The bending load is provided by
some known weight.

I've never seen the other methods described, but they must rely on the
same principle of measuring the bending deflection due to a load, and
then calculating the implied modulus.
Received on Fri Jan 13 2006 - 18:52:25 CET