Re: leaf spring energy

[jmclean@chem.ucsd.edu (James Mclean)]

brian whatcott says:
> I cannot do better than remind the readership of an excellent paperback -
> actually two of them - written by (Professor) James E Gordon.
> "Structures" and "The New Science of Strong Materials".
> This is material more gripping than a mystery, more relevant than watching
> "Titanic", and engaging to the attention.

Thanks, I'll definitely look these up.

> There, one finds in a slim appendix, the royal road to reasonable stress
> calculations - and I will echo his notes on Beam Theory here:
>
> The basic formula for stress s at a point P distant y from the neutral axis
> of a beam is
>
> s/y  =  M/I  = E/r
>
> Where: s is tensile or compressive stress
>       y is distance from the neutral axis
>       I is second moment of area of cross-section about the neutral axis
>       E is Young's modulus ( or stiffness or inverse springiness, if you
> will)
>       r is radius of curvature of the beam at the section we are examining.
>       M is 'moment' or force times perpendicular distance from section of
>          interest.

I hesitate to ask this before looking up the reference, but...
You speak of a neutral axis, where I naively would have expected a neutral
plane:  tension above and compression below.  Is it necessary to have
inhomogeneity 'across' the beam, i.e., along the axis perpendicular to both
the beam length and the bending force?

-- 
--James McLean
jmclean@chem.ucsd.edu
post doc
UC San Diego, Chemistry