Re: ATM AO and Youngs Modulus for glass

[Johan Vanbeselaere <jvb@digilife.be>]

Young's modulus (E) for 
Pyrex 7740  is 6.8 10e10 N/m*m
Duran 50  7.32
Fused Silica 7.32
UlE 7971  6.77
Cer-Vit C-101  9.18
Zerodur  9.06

BK7     8.1


For formules for thin disk, you should state how the disk is supported !
I guess it's on several points, you can easily find formules for disks
on continuous rings, but
on several points FEM should be used.

For instance :
 a plate simply supported at the edge and with a central 
force f follows the law 

w(r) = f.[(R^2-r^2)/2-r^2.ln(R/r) ]/(8.PI.D)

where R is the outer radius of the plate. D=E(t^3)/12(1-v^2) with t the 
thickness.

Do have a look at my homepage related to mirror support, you'll find
links to other
people specialised in these matter !

Johan Vanbeselaere
ACG vzw Belgium
http://www.digilife.be/club/johan.vanbeselaere/atm/optics/mirrorcell/Mirrorcell.htm