Vacuum Chamber Design
Hi Acroduster , as you can see in my previous post the load does not help almost nothing.
You shall consider each side as uniform loaded by 13.75231 pound /inch2 It is the 28"Hg vacuum
It's a heavy load: 258433.4095 POUNDs
Your 28000 lbs load only exert a 0.555428571 pound /inch2
So it does compesate almost nothing from the other side load.
this weight 258433.4095 POUND is applied on the side walls.
at the roof it is 213875.9251 POUND
So the problem is not on the roof or even the floor , guess you do an empty test.
The problem is on the side walls