FEA deflection calc. of vacuum chamber
FEA deflection calc. of vacuum chamber
(OP)
I am using CosmosWorks 2008 for an FEA analysis of a vacuum chamber of dimensions 49" x 49" x 38", with floor and wall thicknesses of 3/4" and top plate thickness of 1.25". My main question has to do with the pressure (vacuum) loading of the interior surfaces @ 29.9 inHg. Would I input +14.7 psig in the direction towards the inside of the box (putting tension on the inside walls)? And also a +14.7 psig on the outside of the walls in the same direction to account for atmospheric pressure outside of the box. Please help, I am not an FEA expert.





RE: FEA deflection calc. of vacuum chamber
corus
RE: FEA deflection calc. of vacuum chamber
Cylinders subject to vacuum can fail by buckling. Flat plates with pressure applied to them can develop membrane stresses due to large deflection. If your FEA doesn't account for these effects, it won't necessarily be useful in modeling the chamber.
RE: FEA deflection calc. of vacuum chamber
if you work in psia, then 14.7 psia outside and 0 inside.
if you work in mmHg(g), the 0 mmHg(g) outside and -29mmHg(g) inside.
etc., etc....
RE: FEA deflection calc. of vacuum chamber
thanks for the replies.
RE: FEA deflection calc. of vacuum chamber
thanks.
RE: FEA deflection calc. of vacuum chamber
RE: FEA deflection calc. of vacuum chamber
thanks.
RE: FEA deflection calc. of vacuum chamber
RE: FEA deflection calc. of vacuum chamber
Y=K(W*R^4)/(E*T^3)
Where
E= elastic modulus
R= long dimension
W= pressure
T= thickness
From what I read, K is dependent on the end supports and the aspect ratio and poisson's ratio. I could not find any table values for K for mild steel with the edges supported.
Please help!!
RE: FEA deflection calc. of vacuum chamber
RE: FEA deflection calc. of vacuum chamber
Thanks everybody for replying to this, you have all been great help!