Re: Just A Question?

[Dick Morrisson <rmorrisson@unidial.com>]

Rhonda, Gene,
Hi.  I would like to try and shed some light on the idea you both brought up.
The problem has to do with the difference between axial and bending stresses.
Using honeycomb between two panels will greatly increase its bending strength
but will do almost nothing for its axial (compressive) strength.  It will
however reduce the tendency to buckle!  This only helps though when the panels
themselves will stand up to the compressive loads.  And at that point (with that
much material) there are easier ways to design around the buckling problem (i.e.
stiffening rings).  Also, it was pointed out before, a 1 atm sub has to weigh
quite a bit to be neutral bouyant so the weight saved in the hull just gets
added to the ballast!

By the way, honeycomb is actually not as strong as one might think.  The reason
it works on the drop skids Rhonda mentioned is it crushes a little, absorbing
some of the impact loading.  Like the crumple zones in a well designed car.

Hope that helps more than it confuses.

Dick Morrisson

HUNTR2@aol.com wrote:

> Welcome Rhonda,
> I always liked the idea of a double hull with corrigated support between the
> hulls, but it must be too hard to engineer, build, test, and maintain.  It's
> been brought up a couple of times but nobody carries it very far.  My GUESS
> is that, for a little greater hull thickness, you can get a lot more
> performance with out all the difficulties and drawbacks (eg, cost) of a
> double hull.   Is that right? anybody....
> Gene Seus