Emile,
Is your data based on a per-weight basis? Because pound-for-pound aluminum
is definitely stiffer than steel , and I'm sure wood is also. If steel was
stiffer than wood, pound-for-pound, it would be used in racing boats,
recreational boats, airplanes, etc. where weight is a concern. Also, are you
talking about forged steel or mild steel? If I recall, personal subs are built
of mild steel.
Steel is STRONG and that is its one redeeming factor. My interest is in
building subs with a max. rating of 250 feet (75.75 meters and ~125psi) and a
crush depth of 500 feet (151.51 meters and ~250psi). I believe that this is well
within the range of a wood-cored composite structure.
You're absolutely correct regarding tensile strength and impact resistance
relations, however steel does not have the highest tensile strength of modern
materials. Kevlar and carbon both beat out steel in this field, and an outer
skin of Kevlar may provide the impact resistance needed. With stresses running
parallel to the surface, even fiberglass might be sufficient. Steel cables are
being replaced by these new materials in many applications- from winch cables to
both standing and running boat rigging. The new materials are showing much less
stretch and greater tensile strength than steel, though they suffer more damage
from abrasion.
Just trying to further the R&D of home-built shallow-water (sub
1000'/303M) 1atm. submersibles.
Risk
In a message dated 1/22/2005 7:26:32 A.M. Eastern Standard Time,
2stroke@hetnet.nl writes:
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