Stress Analysis - Failure Depth of a Thin-Walled Glass Sphere
Assume a sphere of constant thickness, t, and radius, R, under a uniform pressure field P.
The shell is in equilibrium so the internal stress over the area must equal the external applied force, i.e. s A = F
2p s t = p R2 P so s = RP/2t P = rgh
Compressive strength of glass s ~ 26,000 psi