On Sun, 15 Feb 2015 17:25:19 -0600, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Ed Huntress fired this volley in
:


If it were me, I'd build it, stand back, and try it. Crumpling is a
lot better than exploding. g

Yeah.... I'm out to the hardware tomorrow for some end caps and a fitting
to hook my HVAC pump up to it. I figure I'll gradually reduce the
pressure inside until it buckles (or doesn't!G). If it will take -
10psi, I'll be pretty comfortable with it.

It will naturally be stronger in compression (vacuum) than in tension
(pressure).

Except for buckling. It could crumple long before it reaches
compressive yield strength.

Calculating buckling is black magic. When you take a basic statics
course, the instructor sizes you up and decides whether he/she should
even tell you about it, aside from the basic column formula. I took
statics in a technology class (no calculus) rather than an engineering
class, so I never got into it until long after I was out of school.

Be glad we don't have to calculate it.

--
Ed Huntress