spherical pressure vessel FEA

[arthur]

Hi I am doing a FEA on a sphirical pressure vessel, and am having trouble selecting my contraints. I have cut the vessel in half and selected a mirror constraint. Nexted I selected my displacement constraint being the surface that was cut. This gives results that are higher at the edge of the constraint. Does any one know how to properly constrain a pressure vessel.


hfd

 

[ndk]

can you post a snapshot of constraints you put? I thought that it's easier for us to give you some solutions


NDK

 

[arthur]

View attachment 1718


View attachment 1719


Here is a snap shot. I am actually using point constraints not surface and also you can see from the fea pic that there is stress concentrations leading from the point constraint into the vessel.

 

[ndk]

Hi Athur!


Point constraints should only be used in case of beam idealization. It'll cause stress concentration when constrained shell and solid models.


In your situation, I thoughtyou can use 1/8 symetry model (i'm not sure cause the pics are not clear enough).Suppose the symetric plane is in XY (also the cutting plane as shown in the pics). Then you put a surface constrain on that cutting plane and let Dx and Dy "free", all others "fixed".the same procedureforsymetric cutting plane in YZ and XZ.

 

[vijay_sme]

Is there any one to give the details regarding camprofile generation in proe software


My mail is vijay_sme@yahoo.co.in

 

[mhinkkanen]

Hi Arthur!

View attachment 1759

You could use something like this; however - this solution is not absolutely correct around constrained edges. At those locations you should be extra careful while analyzing vessel behaviour.


2006-02-08_180748_vessel.prt.zip
(WF2 model for vessel)

 

[ndk]

It's 1/8 symetric model and here's the result.


View attachment 1762


(WF 2.0 model)


2006-02-09_033643_vessel.prt.rar