In a message dated 5/18/99 2:14:54 AM Pacific Daylight Time,
[EMAIL PROTECTED] writes:
<< I start to be a little bit concerned about all those people claiming and
pointing out that diffraction don't measure a residual stress but a
residual strain.
..............
So, my own idea is that people who don't know how to transform strain in
stress will measure only strain and the other are measuring stresses.
Let me stress the audience about that; may be is that I am an engineer and
not a physicist or chemist.>>
Well, there is nothing wrong being an engineer but I cannot share your
concerns. Not to bore the audience, I just claim that you are just short of a
few quantities to measure stress directly from a diffraction experiment i.e.
of the elastic constants (which one hopes to find conveniently tabulated
somewhere and prays that they apply to the material under investigation). For
measuring strain, on the other hand, the diffraction experiment provides all
the quantities necessary, you don't even have to know the material. So, it
appears that your "own idea" is more a matter of semantics: measuring stress
vs determining stress; got nothing to do who can or cannot do the "transform".
L. Keller
