Upgrade your account to a Community Supporter account and remove most of the site ads.

Reply to thread

Message: <blockquote data-quote="tomBitonti" data-source="post: 5622239" data-attributes="member: 13107">Googling "spherical pressure hull limit"<a href="http://mit.edu/12.000/www/m2005/a2/finalwebsite/equipment/transport/Hull.shtml" target="_blank">LEEAMITe: The Transport Vehicle</a><a href="http://www.sciencedirect.com/science/article/pii/S0951833910000390" target="_blank">ScienceDirect - Marine Structures : An overview of buckling and ultimate strength of spherical pressure hull under external pressure</a>The first gives some nice equations, with this perhaps the most useful:Pe = 1.22 e (t/r)^2Pe = elastic buclking pressuree = module of elasticityt = spherical shell thicknessr = radius to shell midsurfaceThere is a second limit equation ... probably worth running numbers through that, too,to see if there is a different limit which is reached.For a number of materials:<a href="http://www.engineeringtoolbox.com/young-modulus-d_417.html" target="_blank">Elastic Properties and Young Modulus for some Materials</a>Structural Steel: 200 GPaSilicon Carbide: 450 GPaTungsten Carbide: 450 - 650 GPaDiamond: 1,050 - 1,200 GPaIs a diamond sphere practical?  I have no idea, but lets plug in some numbers.e set to 1x10^3 GPa for diamondt = 1m (arbitrarily)r = 5m (arbitrarily)Pe = 1.22 * 1x10^3 GPa * (1/5)^2   = 1.22 * (1/25) * 10^3 * GPa   = 0.05 * 10^3 GPa   = 5 * 10 GPaThat gets us nicely into the middle of the gas layer (which ends at 10* 10 GPa, the gas transitions to a liquid metal, at a depth of 10,000kilometers.If you increase that by a factory of 100 ... then you are well abovethe pressure at the transition, and can enter the metallic region.Still a problem of temperature.I *think* I read that the gas layer is transparent.  Not really sure,but I don't think the metal layer would be transparent.Now, that is for an ideal sphere of solid diamond!  1m thickness and5m radius seems to give you about 8m of interial space (diameter),about 25 feet across.That is an unbroken sphere, too!  Maybe it runs off an special"projection" engine that allows the machinery to be permanentlyinstalled in the center of the sphere.  Putting in passengers seems tobe a problem ...(Edit: Putting carbon in a high temperature high pressure bath of atomic hydrogen seems to be a short lived experiment ... as well, if the reaction can be avoided, hydrogen infiltration would seem to be a problem.)</blockquote>

Verification