Re: New ideas

[Phil Nuytten <72020.572@compuserve.com>]

Hi John:
        Re the 'hydrodynamically-loaded structure' antd the 'accordian'
style hull:  There is a well-respected engineering firm on Oahu, Hawaii,
who proposed a hull style that, at first glance, appeared to be a sort of a
'tesselated/faceted/ bellows', which looks kind of 'sqeeze-box' ish . .it
is actually a very clever discrete element stiffening system . .we played
with some of the numbers and it does provide significantly better
performance than a simple, unstiffened cylinder. It requires  careful
fit-up - not particularly  tight tolerances, but not sloppy - an enormous
amount  of welding, because of the small individual segments, and would not
out-perform a conventional angle ring stiffened design - all things being
equal. Something to bear in mind, tho', for situations where ring
stiffeners are are not appropriate. For those interested: Take a square
steel plate, say six inches on a side - fold it diagonally, corner to
corner, so that, with the crease sitting flat on a bench the corners
describe an angle that is less than 45 degrees. Now grind or mill the edges
so they will decribe the desired circle when butted to an identical 
neighbor. Remember, the  ends of the creases abutt each other! - it's hard
to describe in text, but you wind up with a cylinder where each crease is
interupted by a peak . .so it is not like a parallel or spiral bellows at
all. The hoop stress readings are quite attractive - and the concept is
novel . . .which is what we need a lot more of . .IMOH !!

Regards
Phil Nuytten