Youngs Modulus for Piano wire

[Ric Brekne]

Hi JD.

Well, I ran into a paper which described a fairly sophisticated 
measuring experiment as part of a university project for a student. Its 
results are 1,824 * 10^11 N/mm^2.

Actually, I've run into 4 distinct numbers. roughly
47,000 lbs / mm^2,
45,000 lbs / mm^2
41,000 lbs / mm^2
31,000 lbs / mm^2

For my purposes I can for the moment settle on 45,000 but I would like 
to get some more input on the matter.

Cheers
RicB


At 4:21 pm +0200 27/8/06, Ric Brekne wrote:

 >Hi StŽphane and David.
 >The two different numbers you give illustrate why I asked to begin
 >with. Davids is from McFerrin, and StŽphane gives from a string
 >manufacturer.

I had a letter from a man at R'lau nearly a year ago who had read an
old posting of mine complaining of the quality of their wire:

 >"We are surprised from your negativeÊopinion about our wire.
 > Please be so kind and let us know what we can do to change mind."

I wrote back at length with details of my complaints and suggested I
might be persuaded to change my mind when they achieved the tensile
strength and the quality of polish to be found on wire 120 years ago.
I have heard no more, and I find it very odd that they do not publish
the specifications of their music wire.

As to the coefficient of elasticity of the wire (Young's modulus),
rather than go by unreliable generalized values it is best to measure
it. It is quite simple to find out which of these two figures is
more correct. The more precise you want your figure the more trouble
you'll need to take with your apparatus.

JD