Re: fun with expendable SSTOs (was Re: The 100/10/1 Rule.)



Greg D. Moore (Strider) wrote:

"Rand Simberg" <simberg.interglobal@xxxxxxxxx> wrote in message
news:467893d0.867901416@xxxxxxxxxxxxxxxxxxxx
On Thu, 15 Mar 2007 17:09:34 GMT, in a place far, far away,
henry@xxxxxxxxxxxxx (Henry Spencer) made the phosphor on my monitor
glow in such a way as to indicate that:

In article <45f94239$0$8352$5a62ac22@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
Neil Gerace <geracen@xxxxxxxxxxxx> wrote:
...and because cold metal is stronger than warm
metal and hence can take higher pressures.

Cold tin is definitely weaker than warm tin, though of course it's a bit
weird as metals go and there's none involved here so it doesn't count
:-) (I think cold 'grey' tin has the tetrahedral-covalent diamond
structure but
nothing like the bond strength, while warm 'white' tin is more like a
true
metal.)

I forget the exact story on tin, but yes, phase changes can mean that
you're not dealing with quite the same metal :-) at different
temperatures.

The other joker in the deck is that some metals -- notably ordinary
carbon steel -- become brittle when cold.

IIRC, this was a factor in the loss of the Titanic. Though only one
of many. And I don't always recall correctly...

Ayup, brittle fractures. The big surprise when they started to look at
the actual wreck was that it wasn't a single huge gash like they thought
but lots of small.

As I understand it, the problem wasn't so much the hull plates, but the
rivets that held them together. The shock of the collission sheared a lot
of rivets, and thus seams were started in areas not directly at the site of
the iceberg strike.

--
Pete Stickney
Without data, all you have is an opinion
.



Relevant Pages

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  • Re: fun with expendable SSTOs (was Re: The 100/10/1 Rule.)
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